Firefox 156.0.1LibreWolf hardeningTor built inAuto-updatesWindows

The fastest, most protected browser I know how to build.

Adrian Browser runs on the Firefox engine. Everything that phones home is gone, the interface fits in a single row, memory is handed back while you are not looking, and every private window travels through Tor.

Download for Windows

v0.2.0 · 89.1 MB · Windows 10/11 x64 · Sep 24, 2026 · updates itself

See how it was built
Adrian Browser showing a web page, with navigation, address bar, tabs and window controls in a single dark row
Navigation, address bar, tabs and window controls share one row.
−31%
memory with six tabs open
0
DNS or IP leaks in private windows
1 row
navigation and tabs together
0
telemetry sent anywhere

01 · Origin

Built on Firefox, after a false start on Chromium.

A browser you cannot rebuild in minutes is a browser you stop improving.

Adrian Browser is a Firefox browser: it runs Gecko, the Firefox engine. The very first attempt used Chromium 153, but a single build was estimated at six to eight hours on a Ryzen 5 5500, so that tree was deleted before anything shipped.

The project restarted on the Firefox release branch, with the LibreWolf hardening layer on top and my own layer above that. Nothing is edited inside the Firefox source: settings, theme, privacy and performance live in their own folders, and fourteen small patches hook them in. Interface changes rebuild in about a minute.

Adrian

design · Tor · memory saver · installer

LibreWolf

hardened defaults, policies, no telemetry

Firefox 156

Gecko engine, Mozilla release branch

each layer sits on the one below it

02 · Design

One row, and a layout that knows when to give up.

The Obsidian theme merges navigation and tabs into a single 44px row on a near-black surface with one violet accent.

1200px and wider · one row
under 1200px · two rows

Responsive chrome

Below 1200px, the width of a half-snapped window or a small laptop, the row splits in two: tabs and window controls on top, a full-width address bar below.

Controls never clip

The window stops shrinking at 500px and only the tab strip may compress, so minimise, maximise and close always stay on screen.

One token system

A 4px grid with shared tokens for colour, radius, motion and shadow. Popups, panels, the page loading line, the Update pill and the new tab page share one family.

Own identity

Custom icons, new tab page, branded installer and Windows integration under its own name and profile location.

03 · Performance

Measured, not assumed.

Profiling showed the biggest consumer was not a web page. The extension process was holding roughly 300 MB of JavaScript garbage that nothing ever collected.

Total memory · six tabs · uBlock Origin · Windows 11

Before990 MB
After790 MB
After, idle686 MB

Private working set, summed over all browser processes.

Full refresh rate

Scrolling and animation run at the monitor's own rate, 144 or 165 Hz. The 60 Hz cap that hides you among Tor users applies only while a private window is open.

Memory saver

After 30 seconds in the background, or two minutes idle, every process returns freed memory to Windows. Tabs untouched for 45 minutes sleep until clicked.

Tor only when needed

The Tor client starts with the first private window and exits ten minutes after the last one closes, instead of holding 55 to 90 MB from startup.

Leaner defaults

One spare content process instead of three, a tighter back/forward cache, a 256 MB image ceiling, and a disk cache so sites load fast after a restart.

04 · Private windows

Private windows leave through Tor, or not at all.

A private window is more than a window that forgets. Its traffic takes a different road out of your computer, and it presents a different face to every site.

A private window in Adrian Browser with the green Tor status pill next to the window controls
A private window, connected. The green pill next to the window controls is the Tor status.

How a private request travels

  1. Private window

    its traffic is kept apart

  2. Built-in Tor

    a separate path for every site

  3. Three relays

    no single relay knows both ends

  4. Website

    sees the last relay, not you

Normal windows are untouched and keep your full connection speed. Only private windows travel through Tor, including the lookups that turn a site name into an address.

What a website can see

SignalNormal windowPrivate window
IP addressYour ownA Tor exit relay, different per site
DNS lookupsEncrypted, through Quad9Resolved inside Tor, never locally
User-AgentPlain Firefox 156Identical to Tor Browser
Time zoneYour ownUTC
LanguageYour ownen-US
Screen sizeYour ownThe window, rounded to fixed steps
CPU coresYour ownA fixed, common value
Canvas and audioProtected against known scriptsRandomised per session
WebRTCLocal addresses hiddenDisabled
Third-party cookiesIsolated per siteBlocked
When the window closesHistory and cookies keptEverything is wiped

Fail closed

If Tor is unavailable, private pages simply do not load. They never fall back to your real connection.

One circuit per site

Each site gets its own path through the network, so two sites cannot compare notes by looking at the exit address.

New identity

One click closes the private tabs, clears their cookies, cache and storage, then moves every site to a fresh circuit and exit.

No trace on disk

Private pages are cached in memory only, including media, and the session is discarded when the last private window closes.

Always visible

The Tor status pill

Every private window shows the state of its connection next to the window controls. Its menu holds New identity and Reconnect. When the row is short, the pill shrinks to its icon and keeps its colour.

Tor · Connecting 45%Tor · ConnectedTor · Offline

Verified, not promised

The automated leak test

Every release is driven through a scripted run that browses in a private window and checks what leaves the computer. The release on this page passed all of it.

  • PASSnormal window is not routed through Tor
  • PASSTor is not running before any private window
  • PASSTor started by the private window
  • PASSprivate window exits through Tor
  • PASStime zone spoofed to UTC
  • PASSlanguage en-US
  • PASSUser-Agent matches Tor Browser
  • PASSWebRTC unavailable
  • PASSWebTransport unavailable
  • PASSwindow size bucketed, screen hidden
  • PASSCPU core count spoofed
  • PASSnew identity: private tabs closed
  • PASSnew identity: exit address changed
  • PASSno private lookup left outside Tor

An honest limit. No browser can promise perfect anonymity. Signing in to an account, or opening a downloaded file outside the browser, identifies you no matter which network carried the request.

05 · Changes

What came out, what went in.

Normal windows are hardened too: HTTPS-Only, cookies isolated per site, fingerprinting protection, tracking parameters stripped from links and Global Privacy Control.

Removed

  • Telemetry, studies and remote experiments
  • Pocket, sponsored shortcuts and sponsored suggestions
  • AI chatbot sidebar, link previews and smart tab groups
  • Firefox View, VPN promos and “More from Mozilla”
  • Mozilla's update servers and the default-browser agent
  • Crash reporter uploads
  • DRM playback (Encrypted Media Extensions)
  • Onboarding tours, surveys and feedback prompts

Added

  • Obsidian interface with a single 44px row
  • Bundled Tor client carrying every private window
  • Memory saver for idle and background time
  • Tab sleep for tabs unused for 45 minutes
  • uBlock Origin preinstalled, allowed in private windows
  • DNS over HTTPS through Quad9 with malware blocking
  • Tor status pill with New identity and Reconnect
  • Branded Windows installer and default-apps registration
  • Signed automatic updates, applied with one restart
  • Per-user install that never asks for administrator rights
  • Page loading line and an Update pill when a new version is ready
  • Start menu shortcuts that repair themselves

06 · Updates

It keeps itself up to date.

Adrian Browser updates itself through its own update servers, run by me at adriantnd.ro. Every Firefox engine release, security fix and new feature reaches you on its own: install once, and the browser stays current.

Current version
v0.2.0
served by adriantnd.ro
Last update
Sep 24, 2026
release channel
Firefox engine
156.0.1
Gecko, Mozilla release
Update size
97.9 MB
full package

Always on the current engine

When Mozilla ships a new Firefox release or a security fix, it is rebuilt with the Adrian layer and delivered through the same channel, usually within days.

Signed by me, checked by the browser

Every update is a package signed with a 4096-bit key that never leaves my machine. The browser refuses anything that is not signed with it, whatever the server sends.

In the background

New versions download while you browse, as a small patch when only a few files changed. When one is ready, the menu shows Restart to update, and the restart keeps your tabs.

Safe to fail

The old version stays in place until the new one is complete. A new release can reach part of the users first, and a bad one can be pulled in seconds.

Changelog

  1. v0.2.0Latest

    Sep 24, 2026

    Firefox 156.0.1

    • Automatic updates: new versions download in the background, are verified against the Adrian Browser signing key and apply with one restart
    • Installs per user, so updates never ask for administrator rights
    • Smooth scrolling at the full refresh rate of the monitor (144/165 Hz) in normal windows; 60 Hz only while a private window is open
    • New tab page: shortcut pills stay on one line at every window size
    • A thin progress line shows page loading above the content
    • Wider address bar: below 1200px the toolbar splits into two rows
    • Start menu shortcuts for the browser and for private browsing are restored automatically if they go missing
    • Pages and assets are cached on disk and survive a restart; private windows still never write to disk

  2. v0.1.0

    Sep 21, 2026

    Firefox 156.0.1

    • First release: Firefox 156 with the LibreWolf hardening layer
    • One-row Obsidian interface and Focus new tab page
    • Private windows routed through the bundled Tor client, with New identity and Reconnect
    • Memory saver and tab sleep
    • uBlock Origin preinstalled, DNS over HTTPS through Quad9

07 · Download

Install Adrian Browser

A single installer for 64-bit Windows 10 and 11. It adds Start menu and Desktop shortcuts and can be removed from Windows Settings like any other app.

Download for Windows

v0.2.0 · 89.1 MB · Windows 10/11 x64 · Sep 24, 2026 · updates itself

Verify the file · SHA-256

90c9e31d55686bba6af1791c1ab9a6d67fcb3b0ed38fe04a9ce35397ce4e9dac

Get-FileHash .\AdrianBrowserSetup-0.2.0.exe -Algorithm SHA256

Before you run it

The installer is not code-signed yet, so Windows SmartScreen may warn before it starts: choose “More info”, then “Run anyway”, after checking the hash. Once installed, the browser keeps itself up to date: new versions arrive in the background and apply with one restart.