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Happo

happo.io

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Spec score 9.2 #1 of 26 in Visual Regression Testing Software

What it is

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.

Spec sheet

What it does
Happo performs visual regression and accessibility testing for pull requests by rendering UI states and comparing screenshots.Read 14 Oct 2026 · happo.io
Product
Happo is a visual and accessibility regression testing platform for checking interface changes.Read 28 Sep 2026 · happo.io
Security
Happo says data is encrypted in transit and at rest, conducts regular penetration testing, and treats customer screenshots and related data as confidential with account-level access controls.Read 28 Sep 2026 · happo.io
Support
Support is founder-led by Henric Persson and Joe Lencioni through documentation, email and repository issues.Read 14 Oct 2026 · happo.io
License
The public Happo integration library and legacy happo.io repository are released under the MIT License.Read 14 Oct 2026 · github.com
Headquarters
Stockholm, Sweden; Minneapolis, Minnesota, United StatesRead 28 Sep 2026 · happo.io
Founded
2014Read 28 Sep 2026 · happo.io
Accessibility testing
Accessibility checks run alongside visual tests and can report violations such as insufficient color contrast.Read 14 Oct 2026 · happo.io
Animation testing
Happo can capture animations at synchronized moments and compare changed frames.Read 14 Oct 2026 · happo.io
API authentication
API requests support JWT bearer authentication or HTTP Basic authentication using API credentials.Read 14 Oct 2026 · happo.io
Browser coverage
Supported targets include Chrome, Firefox, Safari, Microsoft Edge, iOS Safari and iPad Safari, with availability depending on plan.Read 14 Oct 2026 · admin.happo.io
CI providers
The CLI auto-detects providers including GitHub Actions, CircleCI, Travis CI and Azure DevOps.Read 14 Oct 2026 · admin.happo.io
CI support
The Happo CLI auto-detects CI providers including GitHub Actions, CircleCI, Travis CI, and Azure DevOps.Read 28 Sep 2026 · happo.io
Company facts
LinkedIn lists Happo as privately held, founded in 2017, headquartered in Northfield, Minnesota, with 2–10 employees and a Stockholm location.Read 14 Oct 2026 · linkedin.com
Company history
The founders began the DiffUX project in 2014, launched an open-source project in 2015 and commercial Happo in 2017.Read 14 Oct 2026 · happo.io
Cypress integration
Happo injects screenshots into existing Cypress tests and runs them in CI.Read 14 Oct 2026 · happo.io
Data handling
The service processes screenshots, Git SHAs, commit metadata, pull-request titles, authors and internal links, with account-level access controls.Read 14 Oct 2026 · happo.io
Documentation
The repository directs users to docs.happo.io for comprehensive documentation and provides setup examples, configuration files and target options.Read 14 Oct 2026 · github.com
Framework integrations
Happo lists Storybook, Playwright, Cypress, and a generic API for custom setups.Read 28 Sep 2026 · happo.io
Funding
Happo describes itself as self-bootstrapped with no venture-capital funding.Read 14 Oct 2026 · happo.io
GitLab integration
Happo added experimental GitLab support with merge-request statuses, historical baseline lookup and cancellation of superseded jobs; self-managed GitLab is supported.Read 14 Oct 2026 · happo.io
Independent package activity
The npm listing shows happo version 6.24.0, 102 published versions and built-in TypeScript declarations.Read 14 Oct 2026 · npmjs.com
Independent package popularity
The npm listing reports about 14,962 weekly downloads for the happo package.Read 14 Oct 2026 · npmjs.com
Independent praise: workflow confidence
LinkedIn users are presented with Happo's benefit of catching visual and accessibility issues in pull requests through automatic cross-browser screenshot comparisons.Read 14 Oct 2026 · linkedin.com
Independent repository adoption
The main GitHub happo repository shows 513 stars and 15 forks.Read 14 Oct 2026 · github.com
Independent repository description
GitHub describes Happo as a cross-browser screenshot-testing service for continuous integration that works standalone or with Storybook, Cypress and Playwright.Read 14 Oct 2026 · github.com
Independent repository status
The legacy happo.io GitHub repository was archived on May 11, 2026 and tells users to install the newer happo package.Read 14 Oct 2026 · github.com
Limit: browser gating
Safari, iOS Safari and Edge coverage is restricted to higher plans rather than included in the free and Starter tiers.Read 14 Oct 2026 · admin.happo.io
Limit: no monetary bounty
Happo's security policy says it does not currently pay monetary bug-bounty rewards.Read 14 Oct 2026 · happo.io
Limit: quota suspension
Free accounts are paused after reaching quota until they upgrade or the next monthly cycle begins.Read 14 Oct 2026 · admin.happo.io
MCP server
Happo offers an OAuth-protected MCP server that lets agents list comparisons, inspect diffs, approve or reject comparisons and report flakes.Read 14 Oct 2026 · happo.io
Native apps
Native iOS and Android screenshots can be uploaded from XCTest, Espresso, swift-snapshot-testing or Paparazzi workflows.Read 14 Oct 2026 · happo.io
Notable news: GitLab
Happo announced experimental GitLab support on September 10, 2026.Read 14 Oct 2026 · happo.io
Notable news: MCP
Happo announced its MCP server for AI-agent review of visual diffs on June 8, 2026.Read 14 Oct 2026 · happo.io
Payment data
Happo says it does not store payment card data and delegates card processing to Stripe.Read 28 Sep 2026 · happo.io
Playwright integration
Existing Playwright suites can capture selected states for Happo comparisons.Read 14 Oct 2026 · happo.io
Public API
Happo exposes a REST-like JSON API under the /api namespace for reports and custom integrations.Read 14 Oct 2026 · happo.io
Repository integrations
Happo supports GitHub, GitHub Enterprise, Bitbucket, Azure DevOps, and GitLab; GitLab support is labeled experimental and includes self-managed instances.Read 28 Sep 2026 · happo.io
Responsive testing
Viewport sizes, maximum dimensions and color-scheme preferences can be configured for targets.Read 14 Oct 2026 · github.com
SDK and CLI
The npm package includes a CLI, TypeScript declarations, ES modules and configuration support for JavaScript, TypeScript, Storybook, Cypress and Playwright.Read 14 Oct 2026 · github.com
Security encryption
Happo states that customer data is encrypted in transit and at rest.Read 14 Oct 2026 · happo.io
Security practices
The security policy says Happo performs continuous scanning, regular penetration testing and targets critical patch remediation within 30 days.Read 14 Oct 2026 · happo.io
Self-hosting
Happo has described an on-premise deployment containing workers, web server, comparison engine and database installed in a customer's infrastructure.Read 14 Oct 2026 · happo.io
Snapshot comparisons
A snapshot is one screenshot of a component variant in one browser, and a Happo run usually happens once per CI build.Read 28 Sep 2026 · happo.io
Storybook integration
Happo provides a Storybook integration for automated component screenshots.Read 14 Oct 2026 · happo.io
Usage limits
When a free account reaches its quota it is paused until the next cycle or an upgrade, while paid plans incur charges for additional snapshots.Read 28 Sep 2026 · happo.io
Visual diff review
Comparisons can be reviewed side by side, as a highlighted diff, or with a swipe between images.Read 14 Oct 2026 · happo.io
Webhooks
Webhooks can notify external systems when comparisons complete or diffs are marked as flakes.Read 14 Oct 2026 · admin.happo.io

Plans and prices

Free Free 5,000 snapshots per month · Chrome · visual and accessibility testing · no credit card or time limit Read 28 Sep 2026 · happo.io
Free Free monthly 5,000 snapshots/month · Chrome · unlimited users · visual and accessibility testing · no credit card Read 14 Oct 2026 · admin.happo.io
Starter $149 a month monthly 50,000 snapshots · Chrome and Firefox · $0.006 per additional snapshot · unlimited users and concurrent runs · accessibility testing · API access Read 14 Oct 2026 · admin.happo.io
Starter $149 a month Monthly 50,000 snapshots · $0.006 per additional snapshot · Chrome and Firefox · unlimited users and concurrent runs · API access · accessibility testing Read 28 Sep 2026 · happo.io
Growth $399 a month Monthly 150,000 snapshots · $0.006 per additional snapshot · Chrome, Firefox, and Safari · unlimited users and concurrent runs · API access · accessibility testing Read 28 Sep 2026 · happo.io
Growth $399 a month monthly 150,000 snapshots · Chrome, Firefox and Safari · $0.006 per additional snapshot · unlimited users and concurrent runs · accessibility testing · API access Read 14 Oct 2026 · admin.happo.io
Pro $749 a month monthly or annual 300,000 snapshots · Chrome, Firefox, Safari, iOS-Safari and Microsoft Edge · $0.006 per additional snapshot · unlimited users and concurrent runs · accessibility testing · API access Read 14 Oct 2026 · admin.happo.io
Pro $749 a month Monthly; annual billing available 300,000 snapshots · $0.006 per additional snapshot · Chrome, Firefox, Safari, iOS-Safari, and Microsoft Edge · unlimited users and concurrent runs · API access · accessibility testing Read 28 Sep 2026 · happo.io
Enterprise Priced on request annual plans available 1M+ snapshots · all listed browsers · unlimited users and concurrent runs · SSO · SLAs · US and EU timezone support · accessibility testing · API access Read 14 Oct 2026 · admin.happo.io

Every Happo plan and price →

Strong points and limits

Strong points

  • Accessibility testing is included on every plan.
  • Integrates with Storybook, Playwright, and Cypress.
  • CLI detects several CI providers.
  • Free plan includes 5,000 monthly snapshots.

Limits

  • GitLab support is experimental.
  • Free accounts pause at the snapshot quota.
  • Paid plans charge for additional snapshots.

Who it suits

Happo suits teams checking component changes in CI and wanting accessibility testing alongside visual comparisons. It also fits teams using its listed frameworks, repository providers, or custom API setups.

Happo in depth

Read the full write-up

Overview

Happo is a visual and accessibility regression-testing service for teams that want to catch interface changes in their development pipeline. It is best suited to teams building around component stories or browser automation; its appeal is the combination of accessibility checks, workflow integrations and substantial snapshot allowances, while browser access is tiered.

Key features

Happo compares screenshots of component variants with pixel diffs, supports cross-browser capture and provides an approval workflow. Each component variant in each browser consumes one snapshot, and a run usually happens once per CI build. A broad component set, multiple browsers or frequent builds can therefore use an allowance quickly, so estimate usage before settling on a plan.

Accessibility testing is included on every tier, including Free. That makes Happo a stronger fit than a visual-only checker for teams that want both types of regression checks in one workflow. Integrations cover Storybook, Playwright, Cypress and a generic API, while repository support includes GitHub, GitHub Enterprise, Bitbucket, Azure DevOps and GitLab. GitLab support is experimental, including for self-managed instances.

The Happo CLI detects CI providers including GitHub Actions, CircleCI, Travis CI and Azure DevOps. Browser coverage spans Chrome, Firefox, Safari, Microsoft Edge and iOS Safari, but the plan determines which are available. Happo says screenshots and related data are confidential, protected by account-level access controls, and encrypted in transit and at rest; it also conducts regular penetration testing. Card processing is handled by Stripe, and Happo says it does not store payment card data. Support is founder-led, with customers communicating directly with founders Henric Persson or Joe Lencioni.

Pricing

The free tier costs nothing and includes 5,000 snapshots per month, Chrome, and visual and accessibility testing, with no credit card or time limit. It is a useful way to start or run a modest workflow, but an account reaching its quota is paused until the next cycle or an upgrade.

Starter costs $149 a month, billed Monthly, for 50,000 snapshots, Chrome and Firefox, unlimited users and concurrent runs, API access and accessibility testing. Additional snapshots cost $0.006 each. It suits teams that need more headroom and Firefox but not the broader browser set. Growth costs $399 a month, billed Monthly, and raises the allowance to 150,000 while adding Safari; it retains the same per-snapshot overage charge and unlimited users and concurrent runs.

Pro costs $749 a month, billed Monthly, with annual billing available. Its 300,000 snapshots cover Chrome, Firefox, Safari, iOS Safari and Microsoft Edge, plus API access, accessibility testing, unlimited users and concurrent runs. This is the appropriate tier when the wider browser matrix justifies the price and allowance. Enterprise has custom pricing, with annual plans available; it starts at 1M+ snapshots and adds SSO, SLAs and enterprise support in US and EU timezones, alongside all listed browsers and the same unlimited-user and concurrency terms. Paid tiers charge for additional snapshots, so usage beyond the included quota has a direct cost.

Platforms

Happo supports Android, iOS, web and API workflows. The browser lineup expands by plan: Free includes Chrome; Starter adds Firefox; Growth adds Safari; Pro adds iOS Safari and Microsoft Edge; Enterprise includes all listed browsers. Teams that require a particular browser should treat that tier boundary as a buying constraint rather than assume the full lineup is included at every price.

Who it's for

Happo fits teams that run visual checks in CI, use Storybook or browser automation, and want accessibility testing included without moving to a higher tier. Its unlimited users and concurrent runs on paid plans are useful where many teammates or parallel builds share the service. It is less compelling for projects whose snapshot volume is hard to predict: free usage stops at the cap, while paid overages are charged per snapshot.

Pros and cons

Pros: Accessibility testing is part of every plan, so it is not reserved for paid customers.

Pros: Framework, repository and CI integrations cover common development workflows, with an API for custom setups.

Pros: Paid plans allow unlimited users and concurrent runs, avoiding seat and parallel-run limits on those tiers.

Cons: Browser availability depends on the plan, with Safari, iOS Safari and Edge requiring higher tiers.

Cons: Free accounts pause at the monthly snapshot quota, and paid accounts incur a charge for each additional snapshot.

Cons: GitLab support is experimental, a caveat for teams relying on that integration.

Alternatives

Visual Regression Testing Software and Browser Testing Software are useful starting points for comparing tools across those categories.

Choose Loki if you want free, MIT-licensed open-source software and can work with its Node 16+ requirement. Screenshotbot is another option, with a Pay-as-You-Go plan priced at $0.01 a month (billed Per screenshot); its stated free allowance is 10,000 screenshots per month for up to five users, with three months of history. Consider Percy if its free plan's 5,000 screenshots per month, unlimited users and unlimited projects suit your workload; its Desktop plan is $199 a month, billed annually.

Roborazzi is a free, Apache-2.0-licensed option available on Maven Central. Sauce Labs Cross-Browser Testing is an alternative for readers considering a paid cross-browser testing service; its Live Testing plan is $39 a month, billed annually, or $49 month to month, with one parallel test. SnapDiff, Argos and Diffy are other alternatives to compare.

Verdict

Choose Happo if you want visual and accessibility regression checks together, need CI and framework integrations, and can match your browser matrix to its tiered plans. Its strongest reason to buy is that accessibility testing is included even on Free and paid plans allow unlimited users and concurrent runs. Look elsewhere if you need the full browser set at a lower tier or cannot tolerate a free account pausing at its cap or paid snapshot overages.

Verdict

Happo combines visual comparisons with accessibility checks and integrations for common development workflows. Check browser availability and snapshot limits against the plan before choosing.

Where Specifiction places it

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