# Percy

> Percy is a visual testing and review platform that automatically detects, highlights, and helps teams review UI changes across browsers and devices with every code change.

Percy is a visual testing and review platform built to help engineering and design teams catch UI regressions before they reach production. Now part of BrowserStack following an acquisition, Percy integrates into existing CI/CD pipelines and development workflows to automate what was previously a manual, error-prone QA process.

## What It Is

Percy is a cloud-based visual testing tool that captures DOM snapshots of web pages and components, renders them across browsers and responsive breakpoints, and compares them against approved baselines to surface visual differences. It targets frontend engineers, QA teams, and designers who need confidence that code changes haven't introduced unintended visual regressions. The platform covers both full web applications and component libraries, and also extends to native mobile apps through App Percy.

## How Visual Testing Works

Percy's workflow follows three stages: integrate, run, and review.

- **Integrate**: Teams add Percy to their stack using officially supported SDKs for frameworks including Rails/Capybara, Ember, React (via Storybook), Vue, Angular, WebdriverIO, and Appium for mobile. Percy also supports all major CI/CD services.
- **Run**: On each commit or pull request, Percy captures DOM snapshots and renders them on its proprietary infrastructure. Snapshot stabilization technology automatically freezes animations, manages custom fonts, and handles dynamic data to minimize false positives.
- **Review**: Percy presents side-by-side visual diffs with automatic diff matching. Status updates are pushed directly to pull requests in GitHub, GitLab, or Bitbucket, keeping the review loop tight.

## Rendering Infrastructure

Percy's rendering engine is a core differentiator. The platform uses a horizontally scalable, custom-built infrastructure designed specifically for DOM snapshotting. Key capabilities include:

- Cross-browser and platform rendering to catch browser-specific visual regressions
- Responsive diff support across multiple breakpoint widths
- Parallelization support for complex test suites running in parallel CI environments
- Zero overhead added to existing CI build times, since Percy handles all rendering server-side

A newer addition, Visual Scanner, allows teams to detect and monitor visual changes across browsers and devices with zero code and no installations by simply providing URLs.

## Integrations and SDK Ecosystem

Percy is designed to be framework-agnostic. Supported integrations span:

- **Test frameworks**: Capybara/Rails, WebdriverIO, Cypress, Playwright, Selenium, Appium
- **Component libraries**: Storybook (React, Vue, Angular, Ember)
- **CI/CD services**: All leading platforms are supported
- **Source control**: GitHub, GitLab, Bitbucket (for status checks and approval workflows)
- **Collaboration**: Slack integration for notifications, webhooks for custom workflows

## Enterprise Capabilities

Percy's enterprise offering targets large teams running millions of snapshots per month. The vendor states a 99.9% uptime SLA for enterprise plans. Security features include encryption in transit and at rest, no storage of consumer PII or production data (Percy integrates only with test environments and mock data), regular third-party security audits, and an invite-only bug bounty program. Enterprise plans include white-glove onboarding support, prioritized ticket responses, and optional phone or video chat support with a 24-hour guaranteed response time.

## Update: BrowserStack Acquisition and App Percy Launch

Percy was acquired by BrowserStack, which the company describes as "the leading web and mobile app testing platform." Following the acquisition, Percy has expanded its product surface with App Percy for native mobile visual testing and the no-code Visual Scanner feature. Pricing and plan management have moved to the BrowserStack platform, and users sign up and authenticate through BrowserStack accounts.

## Features
- Automated visual diffs with side-by-side comparisons
- Cross-browser and responsive snapshot rendering
- Snapshot stabilization (animation freezing, font management, dynamic data handling)
- Automatic diff matching and grouping
- Commit synchronization and baseline management
- Pull request status updates for GitHub, GitLab, and Bitbucket
- Approval and change-request review workflows
- Comments and notifications
- Parallelized CI test suite support
- Slack integration and webhooks
- Visual Scanner (zero-code, URL-based monitoring)
- App Percy for native mobile visual testing
- Component library testing via Storybook
- Percy-specific CSS overrides
- 99.9% uptime SLA for enterprise plans

## Integrations
GitHub, GitLab, Bitbucket, Slack, Storybook, Cypress, Playwright, Selenium, WebdriverIO, Appium, Capybara/Rails, Ember, React, Vue, Angular, Jenkins, CircleCI, Travis CI, GitHub Actions, BrowserStack

## Platforms
WEB, API, CLI, DEVELOPER_SDK

## Pricing
Freemium — Free tier available with paid upgrades

## Links
- Website: https://percy.io
- Documentation: https://www.browserstack.com/docs/percy/overview/visual-testing-basics
- Repository: https://github.com/percy
- EveryDev.ai: https://www.everydev.ai/tools/percy