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If you want a Percy alternative that checks what the app did after a change (requests, state, console) rather than how it looks, Reticle is built for that. If you want AI-filtered screenshot diffs across browsers on every commit, Percy is the stronger choice, and Reticle is not a pixel diff.
What Percy does
Percy, from BrowserStack, captures DOM snapshots from your existing Storybook, Playwright, Selenium or other tests, re-renders them across browsers and widths in its cloud, and diffs them against baselines. Its pitch: "AI-powered visual testing with less noise and 3X faster reviews" (pricing page). A Visual Review Agent, announced in October 2025, summarizes each change in plain language.
Percy tools are exposed through the BrowserStack MCP server for Claude, Cursor and Copilot (docs).
Pricing is public: Free (5,000 screenshots a month), Desktop $199 a month and Desktop & Mobile $599 a month, both billed annually, Enterprise on inquiry (pricing, checked 2026-10-25). The CLI is public; the service is closed.
What Reticle does
Reticle checks an AI coding agent's change from inside the running web app and returns a verdict with evidence. It reads the network calls, the application state and the console, and on React and Svelte it names the file:line to fix.
Your agent calls it through MCP while it works. Flows it drives are saved and replay deterministically, with no model in the loop. It also drives sites you don't own, reading network, console and DOM there; app state and file:line need its SDK in your build. The SDK is open source (Apache-2.0); the hosted platform runs the same checks on previews and pull requests.
Percy vs Reticle at a glance
| Percy | Reticle | |
|---|---|---|
| What it checks | Rendered screenshots against baselines | Network, app state, console and DOM after each step |
| Where tests come from | Your existing test suites and Storybook | Flows your agent (or you) drive, saved and replayed |
| Browsers | Cross-browser and responsive rendering in BrowserStack's cloud | One engine, the one your app runs on |
| Agent integration | Percy tools in the BrowserStack MCP server | MCP tools the agent calls while it works |
| Sites you do not own | Yes, through your tests | Yes (no app state or file:line) |
| Points to the fix | The changed screenshot | The failing request or state, and file:line on React and Svelte |
| Open source | CLI and SDKs only | SDK Apache-2.0; server FSL-1.1 |
| Pricing | Free; $199/mo and $599/mo billed annually | Start free, no card; open-source SDK free |
Where Percy is the better choice
- You care about pixels across browsers. Percy renders on BrowserStack infrastructure across browsers and widths. Reticle runs on one engine and is not a pixel diff; in our benchmark a 2.3% CSS re-tint was caught by a screenshot and missed by Reticle (scorecard).
- You already have a test suite. Percy plugs into the framework you use and adds visual checks to it.
- You want a review workflow with AI noise filtering. Percy's review UI and agent summaries are built for people approving visual changes.
- You buy through BrowserStack. Procurement and device coverage come together.
Where Reticle is the better choice
- The bug does not change a pixel. A double-submitted form, a write that never persists, a console error under a working page. Screenshots of those match the baseline. Reticle reads the request count, the state and the console, so the step fails.
- You want the agent to find and fix it. The verdict names the failing request or state and, on React and Svelte, the source line, so the agent edits the right file before it says "done".
- You want checks without a suite to maintain. Reticle saves the flows the agent drives and replays them with no model in the loop.
- You want it local and open source. The SDK runs on your machine; nothing from your app leaves it unless you link a project.
On 88 seeded bugs, Reticle caught 85 with no false alarms; two of the other three are traps a correct tool must not flag, and one is a genuine miss. The method is in the benchmark scorecard.
Can you use both?
Yes. Percy answers "did anything look different across browsers?". Reticle answers "did this change do what it should, underneath the screen?". They overlap less than the word "testing" suggests.
See why a green check isn't proof for the case for behaviour checks, and the Chromatic alternative and Applitools alternative pages for other visual tools.
Try Reticle in five minutes
Paste one line to your coding agent, and it installs and wires the SDK in your app:
Follow https://raw.githubusercontent.com/reticlehq/reticle/main/SKILL.md
Or run npx @reticlehq/core init yourself. The README has the details.
FAQ
What is the best alternative to Percy?
The best alternative to Percy depends on the job. For another screenshot diff service, look at Chromatic, Applitools, Argos or Happo. For checking that an agent's change worked in the running app, through network, state and console with the source line to fix, Reticle fits. Teams that need both run a visual tool next to Reticle.
Is there an open-source alternative to Percy?
Yes. For visual diffs, Argos publishes its platform under MIT, and BackstopJS is free and open source. For behaviour checks rather than pixels, Reticle's SDK is open source under Apache-2.0 and its server is source-available under FSL-1.1. Percy's CLI is public, but the rendering service is closed.
How is Reticle different from Percy?
Reticle is different from Percy in what it compares. Percy re-renders snapshots across browsers and diffs pixels against a baseline. Reticle runs the flow in the app and reads requests, state and console after each step, so it catches failures that look identical on screen, but it does not diff pixels.
Why Reticle
Your agent says it works. Reticle checks.
- Checks each change inside the running app: network, state and console, not a screenshot.
- Returns a pass or fail with the evidence and the file:line to fix.
- Open-source SDK on your machine, or the platform on every preview and PR.
No credit card required.