Why I Chose Comet Over Dia and OpenAI Atlas: A Hands‑On AI Browser Comparison

Motivation for AI‑enabled browsers

All three browsers are built on Chromium, so extensions, bookmarks, and developer tools work unchanged. The address bar is overloaded with an AI prompt, allowing on‑the‑fly summarisation, content analysis and automated actions without copying text or uploading PDFs.

Dia Browser

Released by the team behind Arc. Provides free access to overseas large language models and a “Skill” library of preset prompts. Initial impression is functional, but several usability problems appear:

Loss of Arc‑specific UI features (persistent site list, clean layout).

Frequent network checks; often shows “region not supported” and forces re‑login.

Stability degrades after repeated checks, leading to abandonment.

Despite these issues, Dia was the first browser that demonstrated the AI‑in‑address‑bar workflow.

Comet Browser

Used for about one month; consistently the most satisfying. Core capabilities:

Integration with Perplexity API, offering a selection of state‑of‑the‑art models.

Two interaction modes – “Explore” (search‑like) and “Experiment” (prompt‑driven).

Address‑bar query syntax allows choosing backend: perplexity: … or google: ….

Voice interaction: speaking a command triggers the same prompt pipeline.

Custom shortcuts: users define a shortcut name and an embedded prompt template. Example definition:

{
  "name": "summarise-page",
  "prompt": "Summarise the main points of the current page in 3 bullet points."
}

Invoking the shortcut runs the prompt without manual copy‑paste.

Task scheduler: a JSON schedule can trigger a shortcut at a specific time, e.g. every day at 09:00 to fetch the latest headlines.

Page manipulation: a shortcut can include DOM‑click commands, enabling the browser to click a “Next” button or download a file automatically.

OpenAI Atlas Browser

Media hype led to early adoption, but concrete tests reveal low success rates for core tasks.

Summarising a WeChat public‑account article fails – the model cannot fetch the article content, while Comet succeeds.

Identifying the most‑viewed B‑site video returns an incorrect result; Comet provides the correct video.

Batch downloading logos from a search result does not execute; the same limitation appears in Comet, confirming the task is currently unsupported.

Bulk downloading photos from an album also fails in both browsers.

Automated subscription cancellation based on topic classification misclassifies non‑AI blogs as unrelated, preventing the intended action.

Prompt‑injection vulnerability demonstrated by @Charly Wargnier: crafted input can override the system prompt and execute arbitrary commands, exposing a security risk.

Overall, Atlas exhibits a success rate below 50 % for the tested scenarios.

Decision

Comparing the three browsers:

Dia offers free model access but suffers from regional restrictions and UI regressions.

Comet provides the richest toolset – Perplexity integration, voice, shortcuts, scheduler, and reliable DOM manipulation.

Atlas delivers media‑driven expectations but fails on basic content extraction and automation, and shows a prompt‑injection attack surface.

Therefore, the workflow that maximises productivity is to adopt Comet and configure shortcuts for repetitive tasks.

Broader Outlook

AI browsers are still in an early stage. Success rates for fundamental operations (content extraction, batch actions) are often below 60 %. The technology promises a unified entry point for AI‑assisted web interaction, but developers need to improve model grounding, regional access handling, and security hardening before it can replace traditional browsers for most users.

Reference: OpenAI Atlas Test Report – https://mp.weixin.qq.com/s?__biz=MzIwNjM2NjQyNg==∣=2247490591&idx=1&sn=5475dd7dbba789b208c84354a3739658&scene=21#wechat_redirect