Lexmount Moli is an open-source headless browser for AI agents, written in Rust and published by Lexmount on GitHub as lexmount/moli. It fetches pages as Markdown, HTML, JSON or a compact semantic tree, runs real JavaScript, and accepts CDP and WebDriver connections. Layout and painting stay off until a task asks for geometry or a screenshot.
The Moli Browser name covers two things. The open-source binary is free under Apache-2.0 or MIT, at your option. Lexmount Browser at browser.lexmount.com is the company's hosted cloud browser, where Moli is one of two engines you can pick alongside Chromium. The README is explicit that the open-source browser works without the cloud service.
A Standalone Kernel
Moli is not a Chromium wrapper. The README lists its own stack: libcurl for networking, html5ever for HTML parsing, V8 for JavaScript, Servo's Stylo for selectors and computed style, Taffy and Parley for box and text layout, and a CPU software renderer for pixels. There is no GUI, persistent window or GPU compositor.
The single source of truth is the native DOM plus style state. Reading text, querying elements, running scripts or inspecting network traffic never triggers layout. The first geometry request builds a layout tree, freezes it and keeps only that latest copy. Screenshots always rebuild from the current DOM and throw the paint state away afterwards.
Cost Switches
| Option | Effect |
|---|---|
| Default | Deterministic mock geometry, no real layout or paint |
--layout |
Real layout, hit-testing, coordinate input, screenshots, screencast |
--resource |
Loads optional images, fonts, audio, video and text tracks |
--profile-dir, --cookie-file, --http-cache-dir |
Turns on only the persistence a job needs |
Getting Started
The latest release is v1.1.17, published October 12, 2026, with builds for Linux, macOS and Windows on x86_64 and ARM64. Install with the shell script from the releases page on Linux or macOS, or the PowerShell script on Windows. The repo also ships a skills folder so a coding agent can install Moli and run a test fetch by itself.
moli fetch --dump markdown --wait-until done https://example.com
moli fetch --dump semantic_tree_text --wait-selector body https://example.com
moli fetch --layout --dump pdf https://example.com > page.pdf
moli serve opens one endpoint for CDP, WebDriver Classic and WebDriver BiDi, with no ChromeDriver needed. Playwright attaches through chromium.connectOverCDP("http://127.0.0.1:9222").
Vendor-Reported Benchmarks
Lexmount publishes its own numbers. On 192 public URLs, Moli returned useful content for 103 pages (53.6%), against 101 for Chrome Headless, at a median 73 MiB of memory versus 773 MiB. On 1,308 comparable tasks in its Lexbench-Headless-Browser suite, Moli 0.1.1 passed 81.88%; Chrome, the reference engine, passed 99.85%. The cloud product page adds that in internal RL workloads Moli used about one-seventh of Chromium's idle memory. All of these come from the vendor and have not been reproduced independently.
Rank History on AI Rank
AI Rank files Moli under Infrastructure, sub-category "Make world agent-ready". The repository was created on August 10, 2026.
| Snapshot | Rank | Stars | 1-day gain | 7-day gain |
|---|---|---|---|---|
| 2026-10-08 | #1 (from #2) | 12,122 | +1,829 | +9,482 |
| 2026-10-15 | #46 (from #18) | 18,212 | +380 | +6,090 |
| 2026-10-16 | #41 (from #46) | 18,594 | +382 | +5,079 |
October 8 was the peak, when it led the daily list ahead of Niko1221/Strata. Growth has slowed since, yet it still adds a few hundred stars a day. Stars show developer attention, not deployments.
→ Project ranking: lexmount/moli on AI Rank — daily GitHub star growth
Scope Limits
Lexmount states that Moli does not aim for pixel parity with Chrome and does not offer high-fidelity Canvas, WebGL or media playback, and not every Chrome screenshot or print mode exists. Unsupported protocol calls return explicit errors. Its own cloud docs suggest starting with Chromium when unsure, and choosing Moli for structure-first jobs that need no extensions, downloads, recording or persistent contexts.
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Prepared with automated editorial assistance and checked against the official GitHub repository, browser.lexmount.com and dated AI Rank data on October 16, 2026. We did not run our own benchmarks for this article.