MOB³ is a compact, self-contained web browser for the terminal

Written in Go, it combines its own HTML parser, CSS cascade and layout engine, ANSI renderer and pure-Go JavaScript runtime to display real web pages, including inline images, without a GUI toolkit or persistent profile. History, cookies, storage and caches live in memory only: closing MOB³ saves nothing.

Warning

MOB³ is not a secure web browser in any way. It has no sandboxing, process isolation, site isolation, CSP enforcement, certificate UI or security hardening, and it has not been audited. Page JavaScript runs in a small, unaudited engine. Do not use MOB³ to log in to accounts, enter passwords, make payments, or handle confidential data. Use it at your own risk.

Try it with Docker:

docker run --rm -it ghcr.io/mob3net/mob3 -graphics blocks

Download and install

Download the latest MOB³ release from GitHub Releases.

Release archives cover Linux (386, amd64, armv6, armv7, arm64) and macOS (amd64, arm64). Choose the archive for your OS and architecture, for example mob3_vX.Y.Z_linux_amd64.tar.gz. Each archive contains the static mob3 binary.

Example:

tar -xzf mob3_vX.Y.Z_linux_amd64.tar.gz
sudo install -m 0755 mob3 /usr/local/bin/mob3
mob3 -version

Using command line options

Start reading Wikipedia in dark mode:

mob3 -dark -reader 'https://en.wikipedia.org/wiki/Vim_(text_editor)'

See all available options with -h flag

Development

Build from source and start browsing:

make
./bin/mob3 https://example.com

Requires Go 1.27 or newer. Interactive mode runs on Linux and macOS terminals; Windows users can run it under WSL. When stdin/stdout are not a terminal, MOB³ automatically falls back to dump mode.

Press ? inside the app for keys, mouse and forms help. Run mob3 -h for the full list of command-line flags. mob3 -version prints the embedded version.

What to expect

MOB³ is a content browser, not a full browser engine. It is happiest with text-focused pages and gets rough on modern JavaScript-heavy apps.

Works well

• Documentation, blogs, news articles, wikis, forums, changelogs and old or server-rendered HTML.
• Headings, paragraphs, lists, links, tables, <pre> blocks, images and common presentational markup.
• Text/search inputs, textareas, single-select option popups and multi-select list boxes, with a visible caret, arrow-key editing, date/time/month/week, range sliders, color swatches, HTML constraint checks, GET and urlencoded POST form submission.
• Common CSS: selectors, cascade and inheritance, box model, margins, borders, backgrounds, text styling, lists, tables, viewport-width @media queries and basic flex rows.
• PNG/JPEG/GIF/SVG/data-URI images when enabled with -graphics (auto, kitty, iterm, or blocks for half-block art). Images are off by default for speed.
• Session-only memory cache for CSS, scripts and decoded images, with a 32 MiB default budget and -cache to change or disable it.
• Light JavaScript: DOM queries and mutation, classList/style, click handlers, timers, alert/confirm/prompt and native <dialog> open/close, same-origin fetch/XMLHttpRequest plus simple CORS cross-origin requests, and in-memory storage/cookies. Script errors show a short JS: Error footer hint.
• JavaScript console (!): tabbed view of logs, requests, cookies and in-memory storage, plus the raw page HTML; evaluate one-line expressions in the page's runtime, with Up/Down history and results appended to the log.
• Reader mode (R, the footer Reader on/Reader off label, or -reader at launch): extracts the main article into a narrow, chrome-free text column, stays enabled across navigation, and restores the normal page and scroll position when toggled off.
• Dark mode (D, the footer Dark on/Dark off label, or -dark at launch): remaps page backgrounds, text, links and borders to a dark palette; images keep their original colors.
• Browser-style toolbar with back/forward/reload/home, history/help buttons, a bookmarks button when -bookmarks is supplied, a config gear and a centered page title.
• Keyboard and mouse navigation, / incremental find (including multi-word phrases) with highlighted matches (also in the console HTML tab), a draggable page scrollbar, history (including a top-right History page listing the session's links), bookmarks imported with -bookmarks from a Netscape HTML export, scrolling, focus, link hover targets in the footer, text selection, and a ! JavaScript console.

Rough edges

• Modern JavaScript apps (SPAs, dashboards, Google search and similar) may show a partial page, a blank page or their no-JavaScript fallback. Pages that rely on ES modules show a status-bar warning that modules are unsupported and suggest reader mode (R).
• Reader mode is heuristic: it can pick too little or too much content on unusual layouts, shows a snapshot rather than live updates, and removes images, forms and other interactive controls. Dark mode keeps images in their original colors and approximates some author color schemes.
• Anti-bot and firewall checks (Cloudflare, CAPTCHA, DataDome/PerimeterX, Imperva/Sucuri, access-denied pages) are generally not usable. A “Site blocked” page is shown instead.
• No video/audio playback, WebGL, WebAssembly, workers, WebSockets, iframes, Shadow DOM, custom elements, real observers or full History API.
• Basic CSS grid rows are supported, along with position:relative, position:absolute and position:fixed; floats, position:sticky, z-index, CSS variables, animations, transitions, generated content, @import and background images are unsupported or approximated as block flow.
• SVG support is partial: text inside SVG, <use>/<symbol>, filters, masks and CSS-in-SVG may be missing. WebP is not supported.
• Oversized images are capped at 60% of the viewport width and 24 rows, preserving their aspect ratio.
• No tabs or automatic downloads; download links and non-HTML responses open a popup with a copyable curl command instead, and multipart/file uploads are not implemented (clicking a file input shows an unsupported notice). Selected page text copies with y through OSC 52 (terminal support required), and the URL can be selected with the terminal.
• Very large pages, stylesheets and images are capped to keep memory and CPU bounded. Style and layout also run under a time budget, so a pathological page is shown partially with a truncation notice instead of freezing the browser. Pages whose timers update the DOM are redrawn a few times per second rather than continuously, and an idle page with no pending timers does not repaint at all.

Contributing

Contributions are welcome. Every pull request must include the broad license-grant CLA statement described in CONTRIBUTING.md; it keeps MOB³ available under both AGPL-3.0-only and a commercial license. The PR workflow checks the statement. The CI workflow runs formatting, vet and tests.

License

MOB³ is licensed under the GNU Affero General Public License, version 3 only (AGPL-3.0-only). Copyright (c) 2026 Milos Stojanovic. See LICENSE.

A separate commercial license is available on request for use without the AGPL's source-disclosure requirements.

MOB³ is provided “as is”, without warranty of any kind. See the warning at the top: this is not a security boundary.

Third-party module licenses are listed in THIRD_PARTY_NOTICES.