Happo vs Percy

Happo checks interface changes with visual and accessibility regression testing. It captures screenshots of component variants in browsers; a snapshot is one variant in one browser, and a run usually occurs once per CI build. Accessibility testing is included on every plan. Framework options include Storybook, Playwright, Cypress, and a generic API. Repository integrations include GitHub, GitHub Enterprise, Bitbucket, Azure DevOps, and GitLab, though GitLab support is experimental. Its CLI detects CI providers such as GitHub Actions, CircleCI, Travis CI, and Azure DevOps. Available browsers vary by plan: the listed options are Chrome, Firefox, Safari, Microsoft Edge, and iOS Safari. The free plan includes 5,000 snapshots per month; once the quota is reached, the account pauses until the next cycle or an upgrade. Paid plans start at $149/mo, with additional snapshots charged on paid tiers. Happo began as a project in 2014, and its commercial product launched in 2017.

Percy automates visual testing by capturing DOM snapshots and assets, rendering them across browsers, and comparing results with earlier snapshots to flag visual changes. Responsive checks use configurable widths, while snapshot stabilization freezes animations and other dynamic elements to reduce false positives. Percy groups snapshots into the same build when tests run in separate processes or on different machines. Its review workflow includes status updates, notifications, comments, comparisons, and automatic diff matching. Listed integrations include GitHub, GitLab, Slack, Storybook, WebdriverIO, and Jenkins. Documented frameworks include Selenium, Playwright, Cypress, Puppeteer, Ember, Appium, and others. Percy documentation describes testing across real devices and desktop and mobile browsers. The free plan includes 5,000 screenshots per month, unlimited users, and unlimited projects. Desktop costs $199 a month, billed annually, for 10,000 screenshots per month; Desktop & Mobile costs $599 a month, billed annually, for 25,000 screenshots per month. Paid plans have fixed screenshot allowances, and additional usage is charged at the overage rate. Enterprise pricing is custom and unlisted.