DarnlyIf you're looking for a TraceBug alternative, or deciding between the two, this page is for you. Both tools start from the same idea: a bug on your screen should become something your AI coding agent can read and fix. They make different trade-offs. Here's an honest look, with TraceBug's facts taken from its own pages on 2 November 2026, and Darnly's updated for extension 0.3.3.
The short version
- Pick TraceBug if you want the most evidence per bug: session replay, network calls, repro steps and a generated Playwright test. Also if you use Firefox, want to export to GitHub or Jira, or want open source.
- Pick Darnly if you want a quick capture (one key, click, one sentence) that saves straight into your project for Claude Code, Codex or Cursor with nothing to set up in the agent, or if your project lives in the cloud and you want a cloud inbox your agent can read.
Side by side
| Darnly | TraceBug | |
|---|---|---|
| Made for | People building with AI coding agents, including people who don't read code | Its Chrome Web Store listing says "For QA and devs". Its home page also names designers and product managers |
| Price | Free | Free, $0. Open source under the MIT License |
| How you capture | One key, click the broken part, say what you expected | Alt+B starts a capture. You can also record once and file several tickets from it |
| What's in a report | Screenshot with the broken part boxed, the element, the page address, your note, console errors and failed requests from the last 60 seconds, slow requests, the steps that led to the bug (automatic, or recorded with a small screenshot per step), and the shape of the data behind the element | Session replay, console errors with stack traces, network calls, repro steps, screenshots with annotation. Optional video and a spoken description |
| Proof the fix worked | Steps for the agent to check its own fix in a browser (Claude in Chrome, Playwright or DevTools MCP). No generated test | Its MCP server can return a generated Playwright test that fails while the bug exists and should pass after the fix |
| Where reports go | Markdown and PNG files in your project's .darnly/inbox/, your clipboard, or an optional private cloud inbox | One offline .html file, plus JSON and PDF downloads and GitHub and Jira exports |
| AI coding agents | Adds AGENTS.md and a skill so Claude Code, Codex or Cursor read the inbox. No MCP needed for local projects | Local MCP server, added with a terminal command. Needs Node 18+ and a folder of exported reports |
| Cloud projects | Cloud inbox with an MCP connector at api.darnly.dev/mcp (Google sign-in) | Not today. Its pricing page has a signup for when cloud sharing ships |
| Browsers | Chrome, Edge, Brave and Arc | Chrome, Edge and Brave (from the Chrome Web Store), Firefox, and an npm SDK for your own app |
| Account needed | No, unless you use the cloud inbox | No |
| Mac apps and simulators | Mac app for Mac apps, iOS Simulator and Android Emulator | Websites |
Where TraceBug is the better pick
TraceBug captures a lot more than Darnly does, and for many bugs that matters.
- A full replay. Session replay shows everything that happened before the bug. Darnly lists your recent steps (what you clicked, where you typed, which pages you opened) and, if you press Record the steps first, a small screenshot per step, but it isn't a replay.
- A check that the fix worked. TraceBug's generated Playwright test gives the agent something that fails before the fix and should pass after. Darnly only gives the agent steps to check the page in a browser.
- Network detail. TraceBug records network calls. Darnly keeps only recent errors, failed requests and slow requests.
- Other browsers and tools. Firefox, Edge and Brave, an npm SDK, and GitHub and Jira exports for handing a bug to a person. Darnly has no Firefox version and doesn't export to trackers.
- Open source. TraceBug is MIT-licensed, so you can read the code and run it yourself.
- Extras. It has in-browser detectors (accessibility, broken images, mixed content, JavaScript errors, failed or slow requests) and an optional AI debugger that uses your own Anthropic or OpenAI key, or a local Ollama.
Where Darnly is the better pick
- What you expected comes first. You box the broken part and write one sentence, so the report is about the thing you care about.
- Bugs go straight into your code folder. Each one is a markdown file and a PNG in
.darnly/inbox/, next to your code. Your agent finds them with no terminal command, Node or MCP setup. Type/darnlyor just say "fix my Darnly bugs", and it works through them. - Cloud projects. If your code isn't on your computer, the optional cloud inbox and its MCP connector let your agent read your bugs. TraceBug doesn't offer cloud sharing today.
- One inbox, with fixed and not fixed. The cloud inbox collects bugs from all your projects, and your agent marks each one fixed when it's done.
- Beyond the browser. The Mac app captures bugs in Mac apps, the iOS Simulator and the Android Emulator into the same inbox.
Using them together
To be fair to TraceBug, capturing a bug with it is quick too, with no account. The extra setup is only in connecting its reports to your agent. If you hit a bug that only shows up after a long path, a TraceBug replay is the fuller record; Darnly's Record the steps first button covers the shorter ones. For everyday "this button is in the wrong place" bugs you find while you build, Darnly is quicker to send. The guide on writing a bug report for AI agents covers what helps an agent most either way.
Want to try Darnly on your next bug? Add it to Chrome. It's free.