How to tame the Windows Thumbnailer

Wait, what?

The Windows thumbnailer is a feature which allow to see previews* of files when you are in thumbnail mode in windows explorer.

Which Windows I need?

Tested with windows10, but I’m pretty sure will work even on 7 and on 8/8.1. Maybe even vista.
Even if the cache is hardly changed, I can’t assure it works with XP or previous. Try on your risk.

What files are covered?

Actually, any media file should be covered, but windows only fetch some of them (due lack of codecs):

  • Audio files (mp3,wma,flac,ogg,..): I don’t the see the point to preview audio files as you can’t listen the preview at all.
  • Image files (png,gif,jpg,bmp,…): Windows cover most of them, but sometimes don’t fetch thumbs for newer file types like for example the .webp.
  • Video files (avi,mp4,mkv,flv): Windows has several troubles here. Why? As several videos use codecs which aren’t shipped with windows, so the preview is not possible.
  • Other files (txt,doc,swf,pdf): These types are a bit particular. So, the thumbnail may work or not as aren’t fetched with the aid of a codec. Txt and doc previews never worked on explorer for what I know. Pdf support is quite partial.

So why I need the guide?

The feature in windows may not work as expected. Why? As windows only generate previews for the codecs which ship with itself and, even worse, perform various clean-up operations to them. So, yes, it generates thumbnails, but it may need to re-create them if the system decide to wipe-out the temp folder or the various thumb.db files.

It removes clutter, what’s the problem?

This may not be a problem if you have folders with less than 1000 files. But if you have a folder in which you are storing a lot of preview-able files, it’s quite sure windows will wipe them very often.

So.. the thumb cache don’t exist?

Indeed it exist. But it is just no persistent. So, if you have folder with a lot of files – lets say more than 10000 – any time you access to it in preview mode, explorer will grab the thumbs again, as windows removed them.

So.. there’s a solution?

Windows doesn’t provide that, but there is a sort of workaround which involve some external tools

  1. A codec pack: You may skip this if you don’t feel comfortable with the operation but some files, especially several video files – mainly .webp, (several) .mp4 and .avi, .mkv, .flv and others – simply won’t have a thumb.
  2. Icaros thumbnailer: A cool software which allows to empower what windows explorer can preview or not. And especially improve the caching system.
  3. An autohotkey script which make easier to fetch thumbs from windows explorer to icaros: when everything is in place, icaros and this small script will work in synergy.

It this safe?

Codecs and software (when clean) usually won’t harm the machine. But, as general rule, follow the tips to avoid any problem: do regular backups, a restore point before install codecs, know what you are doing and uninstall these tool and the codecs if you have issues. The guide come without warranties. But it doesn’t harm my main machine. So the choice is up to you.

My machine is old. Can I still try this?

Depends on how is “old”. More thumbs means more system resources usage during thumb fetches. If it is really old, probably is not suggested. On the other side, folder in preview mode will be faster, as you actually cached the previews: windows don’t have to load them again and again.

Why I need a codec pack?! VLC reproduce everything*!

Is not essential, but highly suggested. VLC player actually reproduce almost everything simply as it uses “its own” codecs: which often are the same found in the codec pack.

# 1 – Which Codec Pack I need?

Kazaa Lite mega codec pack. Why? Is one the most complete codec pack ever made and it allows to choose what you want in the installer. If unsure, let it decide 😉
You can still use the guide skipping this point, but you’ll have several missing thumbs. If you don’t feel comfortable with the operation, please skip this point anyway.

# 2 – Icaros thumbnailer

After codec pack installation, reboot the system and install icaros. Set-up as it follows:

  • Enable thumbnailing if it were disabled;
  • Choose the thumbnail filetypes you want to preview (click on picture icon);
  • Enable dynamic cache, then click on books icon and…
  • Choose cache location (in a drive with enough space);
  • Remove excluded types (if you want to store picture files thumbs too);
  • Set locations where icaros should use its cache. Or where it shouldn’t (below).


# 3 – Autohotkey script

Why I need this? What it does? My security products says it’s infected!!
It’s a macro tool, most of them (all?) are marked as suspicious or virus, but is not.
Feel free to send it to virus total (which will say malicious), whitelist and use it or do the follow operation manually but it would be really annoying with big folders.
The exe is just to avoid you to install autohotkey if you want to try it.
The ahk is the “source code”, so you can view what it does in notepad 😉
The script basically push the down arrow every “x” time to allow explorer to fetch any thumbnail in a folder, so even Icaros can grab them and store in its cache.
Then, when opened, the folder will use the cached ones instead recreating it any single time. Which is even more annoying.
The script could be really better, but I’m not expert on this.
Close the script (taskbar > H icon > exit) when the folder reached the end to avoid pressing down arrow on other apps.

# 4 – Additional notes (may change anytime)

  • Cbr and (most) swf previews don’t work. But they works with mediapreview. Just DON’T check anything else; Like pdf, fetching swf thumbs is slower.
  • Pdf previews needs Acrobat Reader installed. Open it and enable the thumbnail generation, under general in preferences. But support is not very good – and fetching thumbs is slower;
  • Webp images could need a codec to be open-able/preview-able;
  • Rebuild index in icaros needs a lot of time if stored thumbs are a lot (>1gb);
  • Remove cache in icaros imply that thumbs need to fetched again;
  • Probably, would be better put a max-size to thumb folder, as it can easily grow-up.
  • Any tip to improve the script (especially to make it target only windows explorer) is welcome.

Vivaldi MODS [CSS/JS]

Just an article which links several vivaldi mods — as modding section is growing up a lot.

I won’t link everything – almost impossible – but most useful mods found in forum, usually from modding section (sometimes from other forum areas).

Mods are chosen under a “non conflictual criteria”.
So I won’t usually link mods which could break other mods, never tested or broken by recent snapshot updates.
There are several mods: some are just CSS, some others are JS, some are CSS+JS and some others again could be CSS+JS+html with or without a “companion” extension. But you should find any info following the links.
Before start modding, you have to read and understand the pinned thread.
And all the info in the mod thread, or it will likely fail.
Now, we have an additional way to hook mods, if you prefer to avoid fiddle too much with browser.html.
Of course, you’ll still need to hook the injector there.


  • Don’t be tempted to hook every mod. Just choose the ones that are most useful to you.
  • Vivaldi Browser evolve, and mods have to evolve with it. So, check in the relevant thread if the mod linked is still valid for the current version. If you are lucky, you may just find an update for it.



[Bookmark bar text on two rows]

[Bookmark bar mod (text on folder / icon on bookmark)]



[Chromium scrollbars in vivaldi style]

[Chromium pages skin (extension)]

[var(–Color) injector] (will expose vivaldi color themes variables when provided (eg: Linkspanel)



[Change extensions icons with CSS]

[Disable extension buttons (via CSS)] (If you are not using toggle JS mod)

[Extension toggle mod] – [V2 (Show/Hide/Hidden] – [V3 Sets]

[Extensions on footer] (statusbar)



[Footer mod (show as tool menu)]

[Footer on top] – aka known as status bar, custom.css is changed, use the new code. Won’t work with latest snapshot yet.



[Markdown buttons for notes panel]

[Move all panel buttons on top]

[Move hide/show panel button to right (if panel is on right)]

[Links Panel]

[Notes panel enhancement]

[Open panel on button mouseover]

[Panel overlay] (if you use floating panel, just use mode above)

[Semi-Transparent background on favicons]

[Session Panel mod]

[Webpanel zoom]



[Speed dial navigation as a dropdown menu]

[Transparent speed dial folders]

Scaling mods: speed dial handling is complex and not always work as expected, so I’ll leave the various configurations made below. You can test them ONLY one by one. By default, they rely on a fixed UI scale. Not meant to be dynamic.

Most used solutions:

[Pure CSS mod to have smaller dials (110% UI)]

[Speed Mod]

[YASM (Yet Another Speed Dial Mod)]

Just experiments (not working):

[JS/CSS mod for smaller dials] (Another experiment about speed dials)

[Pure CSS hack to have smaller dials] (Legacy and aggressive. I probably won’t update this anymore).



[Audio Icon Mod] (Only Windows)

[Active tab bold]

[Animated (reload) favicon on tab load]

[Background image visibility on dark backgrounds]

[Flash On tab Title Change]

[Hide tab bar when only one tab is opened]

[Pinned tab with custom indicator (for sidetabs)]

[Pinned tab with content (pin icon)]

[Scroll on top hovering .tab .title]

[Semi-Transparent background on favicons]

[Stacked Tabs mod]

[Tabs loading with color highlight]

[Tabs under urlbar]

[Tabs under bookmarkbar]

[Trash button near add button]

[Two rows of text on tabs] (need v2 RC version)



[Background on urlbar buttons]

[Bookmark button (Urlbar)] (This will actually hide the bookmark bar)

[Change toolbar icons with CSS (via background image)]

[Change toolbar icons with CSS (via SVG path)]

[Hide add-bookmark preview (Urlbar)]

(OLD) [Hide home button] (You can now do this via right click)

[Hide text in padlock by default (show on hover)]

[Incognito Button (Urlbar)]

[Move v button to toolbar] – [Left] – [Right]

[Reload button in the urlbar]

[Shrink searchfield when out of focus]

[Striped pageload indicator]

[Sync button in urlbar (from tabbar)] (experimental, may not work)



[Alternative find-in-page bar]

[Better UI buttons] – [WIN] [OSX] (Need native window in settings)

[Change buttons order] [ Urlbar | Footer ] (Vivaldi should store the values in sync so you have to do this only once)

[Compact panel sizes] (test)

[Confirm close mod]

[Resize Quick Commands Windows (F2)]

[Transitions with window accent]

[Vivaldi://experiment color fix (“theme safe”)]

[Vivaldi focus theme]

[Vivaldi Mod for RGB cases] (sadly I can’t test this)

[Vivaldi Themes Import/Export] (And sort!)

[Vivaldi Search Engines Backup/Restore]

[White Flash Fix] (I think this is fixed in Vivaldi now)

[Window background on whole Vivaldi window]


[USER FILES MODS] (Page Actions)
These mods are for webpages and should be placed under user_files. You can then access to them with <> icon in footer. Could be erased at any update, so keep a copy somewhere else.

[Follower tabs] (Method 2)

[Increase video player size]

Dark ChromeCSS [Unpacked Extension]

What is this?
A small unpacked extension I made some time ago to skin chrome:// pages.

Where it works?
Made and usually tested with most recent Vivaldi snapshot, but it should work with any recent stable or snapshot version (Chromium 63+). And on mac/linux, of course 🙂

It’s complete?
It’s a black&white theme but some areas are “brighter” (black&white&gray) to avoid messing too much with material design/chromium colorizations, often not easy to change.
Some advanced chrome:// still may need a bit of tuning but I’m already pretty satisfied.
This also because chromium takes colors from a lot of sources. I’ll fix what I can.

It slowdown the browser?
It shouldn’t. While it inject the css to chrome pages, it does it with chromium native APIs, so it should be quite fast.

I don’t like colors…
Just open custom.css and change them 🙂
If you improve some areas, just change it – and paste your .css somewhere for anyone interested in it.

I need it?
Well, actually is an extension/modding tool. So, if you are not interested in messing with browser css or internal pages, probably you don’t need it.

It’s safe?
I didn’t placed harmful things inside, it’s just a js loader which only inject custom.css to chrome:// pages.
You can disable/remove it anytime without any issue and it shouldn’t corrupt vivaldi in any way.

How to test it (Prerequisites):

  • Vivaldi Browser (or any chromium based browser. But tested only on Vivaldi snapshot&stable)
  • Enable chrome://flags/#extensions-on-chrome-urls (This extension need to access to chrome urls)
  • Enable chrome://flags/#debug-packed-apps (will be easier to inspect what this extension do with dev tools)
  • Copy chromecss folder where you like (I keep it under /Vivaldi/Unpacked/Chromecss/ for convenience)
  • Enable developer mode at vivaldi://extensions/ (Will allow to load the folder in the archive)
  • Load unpacked extension at vivaldi://extensions/
  • Restart Vivaldi.
  • Open any supported chrome:// vivaldi:// internal pages to see what is changed..

 Just hope chromium don’t remove the flag which make this work.

Grab file and test it 🙂

Vivaldi scrollbar mod [Hybrid extension/mod]

* Follow any instruction to avoid vivaldi hangs or color mess in webpages or other extensions.
* Remove hooks and any change in browser.html if Vivaldi is misbehaving.

What is this?
An extension to change the scrollbars following the Vivaldi theme.

An extension..for scrollbars?
Scrollbars are not part of the browser (Vivaldi) but of the webpage, so they need an extension.

Why I can’t use a plain userscript/extension for that?
Actually you can, but it won’t follow Vivaldi theme, as regular extensions can’t access to Vivaldi UI (yet)

PREREQUISITE: To get start with vivaldi modding read the guide to tweaks browser.html

How to install

  1.  [Download the mod]
  2. Open JS folder and look how to install the js mod. Look at the readme too!
  3. Look at the readme in vscroll folder to see how to install the extension
  4. Follow the steps and you are done.

Credits: httpcss.js is originally based on a nice script made from Sporif

Windows 10. A strange beast.

I need windows?
Depends. Some scenarios you might need it — or not.

* You are a gamer.
Software houses are less interested to port their games on linux/mac.
This don’t mean you won’t find cool games, but you know, win is the “default choice” of any PCs.

* Where you work there are only windows machines.
If you can use something different and you know how it works, just do it.

* Devices which work on windows.
Actually, linux should have a lot of wrappers to make the device working.
If not, you are out of luck.

* You have a Windows 10 OEM licence (laptop often have this).
You could still consider a dual boot. Just try not the remove windows partition or you could lose the licence.
Rare, but could happen. It should be saved on UEFI bios now, but be careful is always a good idea.

I don’t play and I don’t want windows 10!
Then try linux. There are lot of distros, just choose one.
If you are even ready to learn some basic commands, it’s quite probably you never have to reformat the whole thing. Just subscribe to the forum for your distro.

Why I can’t stay to windows XP?!
It would be better to avoid. I like XP, I still have it in a virtual machine, but it was released on 2001.
It’s pretty old and outdated nowadays. Security patches and most modern software dropped it.

But get back to windows… =)
Some infos could be old, as usually latest feature update don’t work on my system. Windows mysteries. o_O

Windows downsides:

  • Commercial product (need money to be legally used);
  • Closed source: any mods could be considered EULA violation and cause headaches;
  • Feature updates often are unstable (scroll to see why);
  • 3rd party softwares often mess with windows/programs (if you don’t know how to fix them);
  • Updates mess hard drive partitions (ignore this if you don’t know what they are);
  • They push their modern apps, even if you don’t use them (cortana, onedrive,..); their removal could lead to strange issues. They come back at any feature update, anyway. So is quite pointless removing them.
  • Interface is confusing if you are used to xp or seven.
  • They removed Aero Glass on titlebar. All is flat and sad now.
  • Explorer still need a lot of optimization (still hasn’t dark theme and good cache for big folders).

Windows updates are changed a lot, so here few tips:

  • Preview updates – when you use the update tool – are not a good idea for a stable system.
  • Feature updates are big and require time to be done, so do any work before restart or you have to wait.
  • Service pack don’t exist anymore. Now are called feature updates (but service packs were more stable).
  • Disabling updates/security features is often a bad idea – if you don’t know why are you doing it — but I saw a lot of machines borked by latest feature updates, so generally is also a good idea delay the latest feature updates to allow MS to fix them for most systems (Note: security updates should be always done).
  • Updates could change boot, so if you have more OS (win/linux), better keep them in different hard drives with different boot sectors, or even better different PCs.

Windows updated are changed a lot on their “windows as a service” schema. I’ll do a quick resume:

  • Skip ahead fast ring: Windows Insider version. You’ll get pre-release versions. Nearly untested and highest chance of severe issues.
  • Fast ring: Windows Insider version. Consider it like a windows alpha version. You’ll encounter a lot of bugs, sometimes really bad. I wouldn’t exclude unbooting machines.
  • Slow ring: Windows insider version. Consider it like a windows beta version. You’ll encounter less bugs, some glitches, and sometimes you have to use workaround to do something (regressions).
  • Release ring (+semi annual targeted): Consider it like a release candidate. Some updates come faster but are clearly even less tested.
  • Semi annual build – targeted (ex Current Branch): Windows update default. Most system are fine with this, but sometimes it’s not true. I hope MS is working here.
  • Semi annual build (ex Current Branch Business): Windows update are tested a little more before you get the update. Good compromise between staying updated/working.
  • Long-Term Servicing Channel (ex Long term branch service):  Only on Win10 Enterprise. Feature updates are delayed a lot (2-3 years). Home and small business don’t need this at all. Is just for enterprises which need to control any update to avoid issues.

If you prefer a stable system, I suggest staying on semi annual (not targeted).

Safety tip on rings/branches: If you change the channel, you are not able to get back to the original one without reinstalling the whole OS. So, choose it wisely. Instead a feature update from your ring/branch can be removed within 10 days, so keep an eye if everything it’s working fine and go to previous version quickly if it doesn’t 🙂

Modify system settings: Windows 10 has (still) two settings apps (which is quite confusing and even annoying, I know). The main is called “settings” and it uses ModernUI – while the other, the “legacy” control panel – the one on win7 – it’s a traditional window program – not an app. But probably you have still to use both. For example, admin tools are only in legacy panel. Try to remember any change you do, there. It will save future headaches. The same for any app or driver installed on windows.


Worst bugs I had/seen:

  • Chromium bugs [Win10 1803]: Bug about maximized window (opera fixed before chromium); modern tiles of vivaldi and chrome could be blank at win startup (restart explorer fix this).
  • Gpedit.msc “is closing” [Win10 Pro]: Closing windows require a lot of time, as version 1511 – now obsolete – had this bug.
  • Missing/unworking tiles [start]: Links on start could vanish or stop to work correctly. Remove them and pin again on start. [Windows10 < 1607 ?]
  • Unworking programs: App could stop to work after a major update. Just reinstall it [Windows 10 < 1607 ?]
  • “Faulty” security updates: On rare cases, removing the latest security KB (update) could fix an app. But it should be used as last resource, as is not recommended to remove a security update. [sadly, this is a random – and old – windows issue: last seen on 1511]
  • Modern apps stop to work/are removed: Windows 10 1703. Nasty. And random.
  • Sticky “unused” folder on quick access: This will be on until windows put an option to remove their “user folders”. You can try an hider.

The driver trouble
Windows – and any redmond product – updates itself. Same for most drivers in your machine.

So.. should I update drivers with windows update?
I won’t. Do it only if vendor hasn’t the right driver or if you unsure to what is the right one.

As usually the driver which windows update has, is older than the one you can found on the site of the vendor.

Should I install a driver from windows update if I installed it via vendor site?
No. But Windows will do and you’ll end on a mix of old (from windows update) and new (from site) driver.
In this case, just lock the driver update with this.
If windows update stop to work, try this instead.

Security features
Windows has several security measures. And you should always keep them on. Keep in mind some viruses don’t need admin rights, or can exploit OS to grab them. So you need to be careful always and everywhere 😛

  • Administrator account: Any app can change vital OS parts. And viruses too. Usually only experienced users should use this – but some use people uses standard account, which is slightly more secure.
  • Run as admin: Allow an app/installer to perform admin tasks (often need for an install/upgrade)
  • Standard account: You’re not allowed to change OS vital parts. Or perform any admin task if you don’t use run as admin.
  • Guest account: Similiar to standard, but slightly more restricted. For guests.
  • User account Control(UAC): Every time an action need admin rights, you have to choose allow/unallow. Note: it could be useful only if you read what it says.
  • Windows firewall: Basic protection against intrusion. Keep it on if you haven’t any firewall installed.
  • Windows defender: Protection against viruses. Keep it on if you don’t use third parties antivirus.
  • Secure boot: Prevent using unsigned driver and even some(most) boot sector changes. If you don’t know what it is, keep it on. Some devices – as WindowsRT (arm) – can’t disable it.
  • Smartscreen: Unallow some low level changes. If you don’t know what it is, keep it on.


3rd party security softwares:

Usually, Win10 protection is fine, but if you need more layers of security, you probably are using some of these. These need to be configurated manually to avoid issues with other apps.

Listed from “core security” to “advanced security”. If you are cautious person, you probably won’t need mos of these.

  • Antivirus: Same as Windows Defender, prevent infection.
  • Standalone scanning tools: Best if it has cloud scan (newest engine signature) and multiengine scan (so more chance to detect viruses). Some can scan also browser extensions.
  • Sandbox: Allow to launch an app in a kind of “virtual machine”. So most infections won’t reach your PC.
  • VPN (paid) service: It routes your traffic to stay anonymous, prevent censorship, bypass geolocks and so on. Free services, while they can work, could log you. So they are not really “safe” after all. Some even share IP between users, which is even more insecure.
  • Virtual machine: Virtual OS in your OS. But you’ll be infected if you don’t disable the network on it or if you use sharing folders. So be careful when testing there.
  • Adblocker: Some adblockers can be used system wide. So you need to correctly set it up.
  • Software Firewall: Same as Windows Firewall. It handles incoming/outcoming network traffic.
  • HIPS module: Often called proactive defense. It handles any os process – a kind of superUAC (but often more effective). It’s pointless to use it, if you don’t understand what are saying or their behaviour.
  • Hardware firewall: An hardware firewall to protect your pc. Usually, only need on business or very expert users.
  • Advanced ones: Software or hardware tools which can mitigate with new menaces. Mainly for business.


Risky users habits or “best ways to get an infection on Windows” (most viruses works only here after all).

  • Disabling OS security features without a valid reason;
  • Opening strange attachments in mails. These often has cryptovirus, really bad guys. So always do a scan before opening any attachment and don’t keep them if infected.
  • Install doubt browser extensions/unpacked extensions from untrusty sites (adwares/hijackers viruses).
  • Even some store extensions are infected, so always read their feedback before installing.
  • Install browser plugins from scam sites. Use only real plugin site or your browser addons page to find it.
  • Clicking on scam pages which offer discounts, free things, xxx services or pirated content.
  • Always scan anything which come from p2p platform (torrent/emule) as  it could have nasty things inside.
  • Always scan installers from download sites. Or even better download the product from the actual dev homepage if possible.
  • Toolbars/companions bundled in softwares – are usually a good way to get an adware/hijacker. So, never click next > next > next > accept all > when installing things 😉
  • Always scan memory cards/flash drives you put in your pc avoiding to get infected from there.
  • Social login: when you access somewhere with your social credentials. Probably you won’t be infected, but your data could be used for ads, tracking or spam on your email (which is annoying).

Extensions showcase

My favourite extensions for vivaldi.
Most of them are compatible but some can have minor issues – usually due chromium jumps/minor bugs – but still working.
Look also sticky thread about not working extensions.


  • Even the extensions from the store could be infected;
    Chromium now should check and disable them if they are doing something awkard – like injecting ads in tabs – but checking their feedback before install is always a good idea;
  • Any extension take an amount of system resources (CPU/GPU/RAM) and it often impacts browser performances, pages rendering and their contents.
  • Crx packed extension can be opened with any zip program. They’re actually archives.
  • Unpacked extensions basically are extracted crx. In most cases they don’t do auto updates.

The ones I consider “essential” have a > sign before. But feel free to choose yours.
Unlinked ones can be easily found in store while others have a link to download it.

  • _blank
    Paint a purple border on links which will open in a new tab
  • Auto overlay remover
    If you browse sites with nasty overlays.
    Chromium is working on this
  • > Bulk download images(zig)
    Mass images downloader
  • Chrono download manager
    An alternative to the stock chrome://downloads (with more options) or the vivaldi download panel.
  • Cookie autodelete
    Handle cookies so you can decide what keep and what remove for any site. Won’t clean local storage. Hope Vivaldi will fix this, but not easy I guess.
  • Colorzilla
    Color picker. I hope this will be native.
  • Death to _blank
    Remove all redirects but slow down the browser.
  • > Force background tab
    It will open any tab in background when on.
  • > Flash video downloader
    Used to work, but latest versions don’t work as expected and the older won’t work forever, I fear.
  • > Floating player
    Open video streams in a popup.
  • I don’t care about cookies
    Block annoying “this site use cookies” in European countries where any site should say if they are using cookies.
  • Imagus
    Image preview on mouse hover.
  • > Imtranslator
    A complete translator with useful options.
    A better alternative to G-translate which has issues.
  • MEGA
    Used as workaround to download big files from their servers. Bug was fixed 🙂
  • > OneTab – send tabs – even pinned/stacked – to only one showing a page with their links.
    Help to shrink cpu/ram usage while keeping the tabs in place.
  • > NanoAdBlocker / UblockOrigin
    Poweful adblockers. Read here if you have popup issues
  • > NanoDefender
    Companion of NanoAdBlocker. Unlock sites which locks adblockers.
  • > Pagezipper
    Auto load next page (work on most sites)
  • Popup blocker (strict)
    Handle popups and redirects.
    Could need whitelisting sites you need.
  • > Popout video player
    As floating player, but seems to be more functional.
    Issues on latest snapshot(?)
  • > Recursive bookmark sorter
    The only way to auto sort bookmark bar in A/Z order for both folders and files.
    Workaround for chromium/vivaldi missing feature. Need sorting on “manual”
  • Skip redirects
    In test, no particular impacts of performance. Just skip redirects.
    You might need whitelisting sites you use often.
  • Simple ext manager
    Button for a quick access to all your extensions.
  • > Scriptjager
    Scriptblocker by an_dz. As Umatrix but lighter and easy to use.
  • Smart https
    Load sites in secure protocol or fallback in http.
    Useful but heavy on ram. Some sites could show a garbaged https page (as they are still on http)
  • Stylus/stylebot
    Change css style of webpages (both are fork of stylish)
  • The great discarder/suspender
    Discard/suspend (unload/hibernate) tabs after “x” time with regex support.
    Newer chromium actually discard tabs on low ram/high cpu but don’t allow to choose on which sites.
  • Tab count
    Says how tabs/window did you opened in its button.
    Worth saying also Vivaldi window panel also do this.
  • Tree tabs
    Webpanel which show your tabs in tree style.
  • > Tumblr collage
    A faster way to browse user galleries/archives.
  • Umatrix
    Powerfuil scriptblocker. Read here if you have popup issues.
  • > User agent switcher for chrome
    Often used when vivaldi is mis-detected for a site fault.
  • > Vivaldi forum mod (by luetage)
    Collection of forum mods/themes if you come here often.
  • Video autoplay blocker
    Prevent autoplay of html5 videos: it acts like the old “click to play”.
    Chromium is working on this.

Command line switches

Chromium switches have to be appended to a vivaldi shortcut after vivaldi.exe (or your OS format).
Most of them depend on your OS and are just for debugging, (web)developing or modding the browser, while some others are meant to be used only on chrome – they need specific google API/keys to work – so not meant for chromium based browser, like our Vivaldi.
Some command lines can be enabled also by a flag, and it’s what I prefer whenever is possible as the option is directly “stored” by the browser and not loaded via a shortcut.

Now, some useful switch that can be used in Vivaldi.

Enabling some features:

  • –save-page-as-mhtml (provided also as a flag)
  • –show-cert-link (provided also as a flag) Chromium now does it by default
  • –enable-devtools-experiments Style devtool. Should work on chromium64 or newer.
  • –enable-logging –v=3 –vmodule=metrics=2: Windows ONLY. Place a log in vivaldi profile and a debug window at vivaldi startup. v=0/v=1/v=2 will do a huge txt log.
  • –enable-logging –v=3: Same. Vmodule parameter seems to be necessary on win only.
  •  –process-per-site – This will lower RAM usage but it could increase hangs if you use a lot of tabs from the same site – as it will use a process for each site.
  • –args –ignore-certificate-errors – Not meant to be used on your main vivaldi shortcut as it’ll *always* allow any not secure content from *anywhere* – it’s a risky workaround for few sites/platforms, but it will lower your security alot and could expose users/certificates on machine to data theft and to be hacked. You had be warned. Use it wisely. And only for sites you really, really trust.

Bonus tip: Chromium don’t allow anymore to bypass invalid certificates (“proceed anyway” as firefox does).
If you can’t access to your platform/internal site due an old certificate you can try to type
to access the site.
Keep in mind this should be used only on trustworthy sites or you probably get a malicious certificate placed in your operating system (which is bad) and will probably compromise the machine security.


Allow inspecting UI and extensions

  • –remote-debugging-port=9222 – Then you can inspect tabs/extension/UI at http://localhost:9222/ page.
  • –debug-packed-apps (provided also as a flag)
  • –silent-debugger-extension-api


Cache specific

  • –disk-cache-dir=”D:\Temp\Vivaldi” – Move cache in specific folder. I use it for moving cache outside my SSD drive(C:) while keeping Vivaldi on SSD (for performance reason).
  • –disk-cache-size=1073741824 – Set cache size in bytes (here is ~1GB)


Some experiments for gpu workarounds/enhancement. Couldn’t work at all. As chromium often have troubles on several GPU I don’t advise to test them (they seems to be a placebo). 

  • –enable-features=CheckerImaging
  • –enable-native-gpu-memory-buffers
  • –enable-zero-copy  (provided also as a flag)