Reliable
Every step is checked before the next
Independent Judges read the screen and confirm a step worked before Sai moves on. That is how Sai reached 79.38% on OSWorld 2.1, the highest partial score on the official leaderboard.
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Sai API vs Browser Use
Browser Use is a hosted web-browsing agent with cloud browser infrastructure and an MIT open-source library: send a prompt and it works in a cloud Chromium browser. The Sai API is a computer-use agent on a full computer, so the same task can cross websites and desktop apps. Send a task in plain English and get the result back.
- Highest partial score on OSWorld 2.1
- 79.38%
- per task, the only cost published on the leaderboard
- $14.34
- to add Sai to Claude Code, Codex or Cursor
- 1 command
Sai API vs Browser Use, side by side
As of October 2026
| Capability | Sai API | Browser Use |
|---|---|---|
| What you get | ||
| Product | A working computer-use agent (Sai) behind one API | Hosted web-browsing agent (Cloud API) plus browser infrastructure and an MIT open-source library |
| Computer included | Hosted Windows or Linux cloud computer, or your own Mac or Windows with the Sai desktop app | Yes, a cloud browser (hardened Chromium) plus a 1 GiB workspace. No desktop VM |
| Operating systems | Windows or Linux in the cloud; macOS and Windows on your own machine | Browser only (Chromium) in the cloud |
| Native desktop apps | Yes: desktop apps on Windows, Linux and macOS, not just a browser | No in the cloud API (experimental local macOS harness only) |
| Agent loop and action execution | Built in: send a task in plain English, get the result | Yes: send a prompt, the hosted agent runs to completion |
| Setup / time to first task | Create an API key, add one MCP command (about a minute) | Low: API key, pip/npm install browser-use-sdk, one call |
| Reliability and cost | ||
| Benchmark | Highest partial score on the official OSWorld 2.1 leaderboard: 79.38% (Sai w/ Claude Opus 5, 500 steps, Oct 2026). Binary success 41.67%, #2 behind Claude Opus 5 (44.33%). Trajectories public on Hugging Face | Online-Mind2Web 97% (Mar 2026, own judge); WebVoyager 89.1% (Dec 2024). Web benchmarks, not OSWorld |
| Step verification | Independent Judges check the screen before each next step | Not documented as a named feature |
| Pricing | Credits per request. Free plan: one shared Windows cloud computer with daily limits. Paid: dedicated computers and top-ups. | Pay as you go: browser $0.02/hr; residential proxy $5/GB; agent runs = model cost + 20% |
| Cost per task / cost drivers | $14.34 per OSWorld 2.1 task, the only leaderboard entry with a published cost (OSWorld 2.0: $15.70) | Model tokens (largest), proxy GB, browser minutes; BYOK adds a 0.2× orchestration fee |
| Repeat runs | Learns a workflow once, then replays it as self-healing code: up to 90% fewer tokens on repetitive tasks | Rerunnable scripts that self-repair when a site changes; reruns still call a model |
| Control and safety | ||
| Human approval | Built in: approve, approve for this task, or deny; link-only approvals for sign-ins and credentials | Documented pattern: pause, human acts in live view, resume. No approval API |
| Live view / takeover | Live view to watch tasks and answer approvals. No manual takeover | Interactive live view (takeover), optional MP4 recording, share links |
| Data and compliance | SOC 2 Type II and HIPAA. Runs on Simular's cloud computer or your own machine. | US or EU (Frankfurt); SOC 2 Type II; ZDR and HIPAA on Enterprise |
| Operations | ||
| Sessions and persistence | Context carries across tasks on a computer; reset with new-session. | 4-hour hard browser timeout; profiles keep logins; workspaces keep files (950 MiB) |
| Concurrency and limits | One task per computer at a time; 60 messages per hour; paid plans add dedicated computers | 10 concurrent sessions at $0 spend, up to 1,000 at $25k; Enterprise custom |
| Fit in your stack | ||
| Coding agents / MCP | Official MCP server (@simular-ai/sai-mcp) for Claude Code, Codex, Cursor and any stdio MCP client | Hosted MCP server plus CLI for Claude Code, Codex, Cursor, Windsurf |
| Model choice | Model-agnostic: Anthropic, OpenAI, Google, MiniMax, xAI, OpenRouter, or auto | Many models (Anthropic, OpenAI, Gemini, Grok, DeepSeek…) and BYOK |
| SDKs / languages | HTTP API (curl, Python, Node examples) plus the MCP server on npm | Python and TypeScript SDKs, REST, CDP (Playwright/Puppeteer/Selenium) |
| Free tier | Yes: free plan includes a shared Windows cloud computer (daily limits) | $1 one-time credit; open-source library is free |
What unifies the Sai API
Four things every task gets, without extra code.
Efficient
Learn once, repeat for less
The first run works the task out. After that, Sai replays it as self-healing code instead of reasoning through every screen, using up to 90% fewer tokens on repetitive tasks.
Ready
A whole computer, already running
Sai works on a hosted Windows or Linux cloud computer, or on your own Mac or Windows machine. It opens apps, clicks and types in desktop software that has no API. No VMs or display drivers to manage.
Composable
Plugs into the agents you already use
Add Sai to Claude Code, Codex or Cursor with one MCP command, or call one HTTP endpoint from any language. It pauses for your approval before sign-ins and other sensitive steps.
Frequently asked questions
What is the difference between the Sai API and Browser Use?
Browser Use runs its agent in a cloud browser: a hardened Chromium with a 1 GiB workspace and no desktop VM. The Sai API runs Sai on a whole computer, a hosted Windows or Linux cloud computer or your own Mac or Windows machine, so a task can use websites and native desktop apps. Both take a task in plain English and return the result.
Can Browser Use operate desktop apps?
Not through its cloud API. Browser Use has an experimental macOS harness that runs locally only. Sai operates desktop apps on Windows, Linux and macOS as well as websites.
How is Browser Use priced compared with the Sai API?
Browser Use is pay as you go: browsers at $0.02 per hour, residential proxies at $5 per GB, and agent runs at model cost plus 20%; bringing your own key adds a 0.2× orchestration fee. The Sai API is billed in credits per request. On OSWorld 2.1 Sai completed tasks at $14.34 each, the only cost published on the leaderboard.
How do the benchmarks compare?
Browser Use reports web benchmarks: Online-Mind2Web 97% (March 2026, scored with its own judge) and WebVoyager 89.1% (December 2024). Sai has the highest partial score on the official OSWorld 2.1 leaderboard, 79.38%, which tests full computer tasks rather than websites only, so the numbers are not directly comparable.
Do both work from Claude Code, Codex and Cursor?
Yes. Browser Use has a hosted MCP server and a CLI for Claude Code, Codex, Cursor and Windsurf. Sai has an official MCP server, @simular-ai/sai-mcp, for Claude Code, Codex, Cursor and any stdio MCP client.
How do approvals and live view work?
Browser Use documents a pattern where the agent pauses, a person acts in the interactive live view, and the run resumes; there is no approval API. Sai asks before consequential steps with approve, approve for this task or deny, and sign-ins and credentials are approved through a link. Sai’s live view lets you watch and answer approvals but not take over.
When is Browser Use the better choice?
When the work stays on websites and you need anti-bot strength (stealth Chromium, residential proxies, CAPTCHA solving), up to 1,000 parallel sessions, $0.02-per-hour browsers, an MIT open-source library or a wide choice of models. Choose the Sai API when the task needs a full computer with desktop apps, step checks and built-in approvals.
How do I get started with the Sai API?
Sign in at platform.simular.ai and create an API key. Add Sai to Claude Code, Codex or Cursor with one MCP command, or call the HTTP API from any language. The free plan includes a shared Windows cloud computer with daily limits.
Skip the harness. Ship the agent.
Get an API key in a minute, or talk to us about running Sai at scale.