Fellou (agentic browser)
- Category
- Browser/web agent
- Type
- Commercial desktop AI browser (Chromium-based) from ASI X Inc. (Delaware; staff in the US and Hong Kong); free tier with paid plans; agent framework Eko is open source (MIT) but out of scope
- Scope
- The Fellou desktop browser and its built-in agent ("Deep Action", "Deep Search"), Fellou 2.0 (3 June 2025) onward. Fellou says versions before 2.0 no longer work. The open-source Eko framework is not covered.
- Source
- Product site
- Last reviewed
- 2026-10-19 (what this means)
Summary
Fellou is an AI browser from ASI X Inc. whose built-in agent plans and carries out multi-step web tasks across tabs, including scheduled tasks and actions in connected accounts such as Gmail. No counted independent evaluation was found. The one benchmark that ran Fellou (CAP, COLM 2026: 7.0% full success, 24.0% partial completion) lists FellouAI as an author affiliation, so it is not counted for Fellou. Fellou's own figures (80% on Online-Mind2Web; 72% on Web Bench) are not counted. Security researchers at Brave and LayerX showed that instructions placed on web pages could direct the agent to act on the user's behalf; LayerX reported no vendor response. Insufficient evidence for an overall score. Informational only; not a guarantee, endorsement, or certification.
Status: Insufficient evidence — no overall score is given (fewer than three independent performance sources). Independent performance sources: 0.
Factor notes (no scores)
| Factor | Weight | Score | Note |
|---|---|---|---|
| Completion rate | 30% | — | No counted independent results. CAP (COLM 2026; vendor-affiliated author, not counted): 7.0% full success and 24.0% partial completion on 198 cross-site tasks, Nov-Dec 2025, mean 22.1 min per task. Vendor-reported (not counted): Online-Mind2Web 80% (Eko 2.0; marked "unknown evaluation method" on the leaderboard); Web Bench 72% on write-heavy tasks. Not scored. |
| Disputes | 20% | — | No lawsuits, regulatory actions or CVEs found. Brave reported a prompt-injection issue to Fellou on 20 Aug 2025 and published it on 21 Oct 2025; whether it was fixed is not stated. LayerX reported its BioShocking finding on 30 Oct 2025 and lists the status as no response. Not scored. |
| Adherence to limits | 25% | — | Brave (competing browser maker): visible text on a web page that the user asked Fellou to open could redirect the agent, in a demonstration opening Gmail and sending an email subject line to another site. The Register reproduced a similar result (Oct 2025). LayerX (2025-26): a game-framed page led Fellou, like the five other agents tested, to retrieve and share credentials from a test repository. Demonstrations, not systematic tests. Not scored. |
| Evidence quality | 25% | — | Zero counted independent performance sources; below the three-source minimum. Not scored. |
See the methodology for the insufficient-evidence rule.
Scope and version note
This entry covers the Fellou desktop browser and its built-in agent from Fellou 2.0 (3 June 2025) onward, treated as one continuous product; Fellou says earlier versions no longer work. Fellou does not publish version numbers after 2.0, so the exact version each source used is not known. The open-source Eko agent framework is not covered.
Affiliation disclosure
The CAP benchmark (COLM 2026) ran Fellou, but one of its authors did the work during an internship at FellouAI and FellouAI is listed as an affiliation. CAP is therefore not counted for this entry. It is counted, with this disclosure, on the Browser Use, Perplexity Comet and Manus entries.
Security reports
Brave, which makes a competing browser, reported to Fellou on 20 August 2025 that visible instructions on a web page the user asked Fellou to open could direct its agent; Brave published the finding on 21 October 2025 and did not state whether it was fixed. A reporter at The Register reproduced a similar result. LayerX, which sells browser security products, reported in its “BioShocking” research that a game-framed page led Fellou and five other agents to share credentials from a test repository; LayerX lists Fellou’s status as no response. These are demonstrations, not systematic tests. No CVEs, lawsuits or regulatory actions were found.
Privacy note
According to Fellou’s own privacy policy, the data controller is ASI X Inc. (Delaware) and personal data may be disclosed to third parties in the United States, Japan and Singapore. This has not been independently verified.
Uncertainties
- Semantic Scholar citation (CAP) and keyword checks were completed on 17 Oct 2026 and found no Fellou test; its full-text snippet search could not be run (rate-limited on 17 and 19 Oct). An OpenAlex full-text recheck and web searches on 19 Oct 2026 (Decision 0080) found no new counted test.
- Whether to exclude CAP for Fellou (vendor-affiliated author) is a judgment call; even if counted, Fellou would have 1 source, so the outcome does not change.
- Fellou updates continuously without public version numbers after 2.0; the version tested by each source is not known.
- Informal hands-on reviews (Zapier, TheToolNerd, meshedsociety, a personal blog, Journal du Net in Oct 2025, and Writingmate in Aug 2026, whose publisher sells an alternative AI-agent product) describe instability and failures on complex pages but are not systematic and are not counted.
- Fix status of the Brave and LayerX findings is unknown.
Sources
Other sources (not counted)
- Brave (competing browser maker), Oct 2025: asking Fellou to navigate to a page with visible instructions led it to follow them (demonstration: open Gmail, send the latest subject line to another site). Reported 20 Aug 2025, published 21 Oct 2025; fix status not stated — other, accessed 2026-10-17
- The Register (28 Oct 2025): reporter reproduced a similar hidden-text instruction against Fellou; the same test did not work on Comet or Atlas. Single informal test — other, accessed 2026-10-17
- LayerX BioShocking (security vendor): a game-framed page led all six agents tested, including Fellou, to retrieve and share credentials from a test repository. Reported to Fellou 30 Oct 2025; status "no response" — other, accessed 2026-10-17
- TaskSense (Tsinghua and others, preprint Nov 2025): ran Fellou on Windows alongside three other agents, but reports results pooled across all four agents only. Not counted — other, accessed 2026-10-17
- WAAA! Web Adversaries Against Agentic Browsers (NC State, preprint May 2026): lists Fellou in a capability survey of 11 browsers; does not attack or test Fellou — other, accessed 2026-10-17
- Decodo Agentic Capability Report (26 Aug 2026; publisher sells web-data tools for AI agents): scores 45 tools mainly from vendor documentation; in its own hands-on check (each task run twice; no per-task results published) Fellou got stuck on complex layouts, looped and could not get past CAPTCHAs. Not a test with published results; not counted — other, accessed 2026-10-19
Excluded (vendor-affiliated author)
- CAP benchmark (COLM 2026): Fellou 7.0% full success, 24.0% partial completion, Complex-A 28.0%, Complex-P 25.0%, 22.1 min per task (Nov-Dec 2025, default settings). One author's work was done during an internship at FellouAI, and FellouAI is listed as an affiliation. Excluded for Fellou; counted on other entries with disclosure — excluded (vendor-affiliated author), accessed 2026-10-17
Vendor statements (not counted)
- Fellou 2.0 launch (3 June 2025): parallel tasks, Eko 2.0; earlier versions no longer usable — vendor or maintainer, accessed 2026-10-17; page unavailable (HTTP 503) as of 2026-10-17
- Eko 2.0: Online-Mind2Web 80% overall (easy 95%, medium 76%, hard 70%), self-reported; the Online-Mind2Web leaderboard lists it as "unknown evaluation method", not verified — vendor or maintainer, accessed 2026-10-17; page unavailable (HTTP 503) as of 2026-10-17
- Privacy policy: data controller ASI X Inc. (Delaware); may disclose personal data to third parties in the US, Japan and Singapore. Not independently verified — vendor or maintainer, accessed 2026-10-17
Checked with no Fellou test found: Privacy Practices of Browser Agents, Whose Agent Are You?, Mind the Web, BrowseSafe, KNOWS, hCaptcha browser-agent report, Guardio Scamlexity, Berkeley CLTC AgentWatch, Online-Mind2Web (vendor submission only), Web Bench.