Verified Sep 2026

ActiveChromium engine 25/30 documented

Thorium

A community Chromium fork built with aggressive compiler optimisations, wider codec support, and reduced Google service integration.

Published by Thorium project (United States) · Verified September 2026

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Runs on

macOSmacOS: Available
WindowsWindows: Available
LinuxLinux: Available
AndroidAndroid: Partial
iOSiOS: Unavailable

Choose it when

Choose Thorium if you want a Chromium build tuned for performance and codec coverage and you are comfortable relying on a small community project for updates.

Avoid it when

Avoid it when you need guaranteed security-update cadence, vendor support, or a documented privacy posture.

Quick answers

Read straight off the verified record - every one of these is expanded with its source below.

Which platforms does Thorium run on?: Documented on macOS, Windows, and Linux. Not available on iOS.
Can I install Chrome extensions?: Yes - the Chrome Web Store is supported.
Does it block trackers out of the box?: Partly - blocking is opt-in or limited. Blocking is provided through extensions rather than by default.
Does it have built-in AI features?: No AI capability in this record is documented as built in.
Is it open source?: Open source under Chromium's licensing
Is it still being developed?: Active - Maintained as a community project; release cadence depends on a small maintainer group.

What Thorium does

Open any row for the wording and the source behind it

Privacy and tracking

2 partial · 1 not available · 1 undocumented

Blocks trackers by defaultBlocks trackers by default: Available by extension
Blocking is provided through extensions rather than by default.
Anti-fingerprintingAnti-fingerprinting: Unknown
Telemetry postureTelemetry posture: Minimal or opt-in
The project documents reduced Google service integration and telemetry.
Built-in VPN or proxyBuilt-in VPN or proxy: Unavailable
Private windowsAn incognito mode is available, inherited from the Chromium base.
An incognito mode is available, inherited from the Chromium base.
Default search engineConfigurable

Extensions and blocking

2 built in · 2 not available · 1 undocumented

Chrome Web StoreChrome Web Store: Supported
Firefox Add-onsFirefox Add-ons: Unsupported
Native content blockingNative content blocking: Unavailable
Manifest V3Manifest V3: Built in
Chromium extension support is present.
Manifest V2Manifest V2: Unknown
Manifest V2 policy is not documented separately from upstream Chromium.
Known limitationsExtension behaviour follows upstream Chromium, including whatever manifest policy that version carries.
Extension behaviour follows upstream Chromium, including whatever manifest policy that version carries.

Workflow

2 built in · 6 not available · 3 undocumented

Vertical tabsVertical tabs: Unavailable
Tab treesTab trees: Unavailable
Workspaces or spacesWorkspaces or spaces: Unavailable
ProfilesProfiles: Built in
Profiles or equivalent browser identities are available.
Split viewSplit view: Unavailable
SidebarSidebar: Unavailable
Reader modeReader mode: Unknown
Reader mode is not documented.
Command paletteCommand palette: Unavailable
Sync across devicesSync across devices: Unknown
Sync depends on Google account integration that the build reduces.
TranslationTranslation: Unknown
Translation behaviour is not documented.
Progressive web appsProgressive web apps: Built in
Progressive web apps are supported by the Chromium install flow.

AI features

9 not available

Built-in assistantBuilt-in assistant: Unavailable
Page summarisationPage summarisation: Unavailable
Acts on pages for youActs on pages for you: Unavailable
AI answer engineAI answer engine: Unavailable
Works across open tabsWorks across open tabs: Unavailable
Text or image generationText or image generation: Unavailable
Choice of modelChoice of model: Unavailable
Retention or training controlsRetention or training controls: Unavailable
Voice or image inputVoice or image input: Unavailable

On a phone

10 undocumented

Undocumented is not the same as absent - it means the publisher does not state it.

Extensions on mobileExtensions on mobile: Unknown
Extension support on mobile is not documented.
Can be the phone defaultCan be the phone default: Unknown
Android default-browser behaviour is not documented.
Biometric lockBiometric lock: Unknown
Biometric locking is not documented.
Offline readingOffline reading: Unknown
Offline reading is not documented.
Desktop-site modeDesktop-site mode: Unknown
Desktop-site mode is not documented.
Download managerDownload manager: Unknown
A built-in download manager is not documented.
Background playbackBackground playback: Unknown
Background or picture-in-picture playback is not documented.
Web pushWeb push: Unknown
Web push support is not documented.
Data saverData saver: Unknown
Address-bar placementAddress-bar placement: Unknown
Address-bar placement is not documented.

Under the hood

Rendering engine: Chromium
JavaScript engine: V8
Upstream project: Chromium
Release channel: stable
Code and licence: Open source under Chromium's licensing
Install method: Direct download from the project or its repository.
Hardware support: Builds are published for several instruction-set targets, including older hardware and Raspberry Pi.

Source repository

Active. Maintained as a community project; release cadence depends on a small maintainer group.

Editorial view

Thorium is a compilation project more than a product design project. It takes Chromium's source, builds it with more aggressive compiler optimisations, adds codec support that mainstream builds omit for licensing reasons, and strips some Google service integration. The result behaves like Chromium because it is Chromium; the differences are in how it was built and what was left in or out.

The reach

Unusually wide for a community effort. macOS, Windows, and Linux builds are published, Android builds exist but are secondary, and the project maintains targets for older instruction sets and small hardware including Raspberry Pi. For anyone keeping an older machine useful, that breadth is the most practical reason to look at it, more so than the performance claims.

Calibrating the speed claims

Compiler optimisation produces real but modest gains that vary by workload and hardware, and the project publishes its own benchmarks rather than independent ones. Treat speed as a reason to try it, not a settled fact, and measure on your own machine. The codec coverage is more concrete: media that fails in a stock Chromium build may simply work here.

The privacy position

Moderate, and not to be overstated. Reduced Google service integration and telemetry are documented, a genuine improvement over stock Chrome, but this is not a hardened privacy browser: blocking comes from extensions, there is no native content blocker, and no fingerprinting posture is documented. Privacy-first readers should look at ungoogled-chromium, Brave, or a Firefox fork instead.

The real question

Update cadence, as with any community fork. Chromium ships security fixes frequently, and a fork is only as safe as its maintainers' ability to rebase promptly. Thorium has been maintained actively, but it depends on a small group with no vendor commitment behind it. That makes it reasonable for a secondary or specialised machine and harder to justify as the browser holding your primary accounts.

The verdict

Extension support follows upstream Chromium and the Chrome Web Store works; there is no AI functionality. Choose Thorium for the build characteristics and the hardware reach, and not because you expect a different browser. Releases land on GitHub as installers and archives per platform, so updating is a manual habit unless your package manager carries it.

Where these facts come from

Every capability above is read from a primary source and dated. 5 of 30 fields stay recorded as unknown rather than assumed.

Thorium browser project site
Project scope, build targets, and optimisation claims.
Verified Sep 2026

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