Overview
Local visual review with 20 Free workflows per month: all five tools on Chrome and limited features on Firefox 153+.
SnapDiff brings visual A/B testing, localization testing, responsive testing, accessibility testing, and UI testing into one local-first extension. All five are available on Free in Chrome, within 20 completed workflows per month. Firefox 153+ is a new limited-feature desktop target: it supports capture, comparison, UI review, annotations, exports, and optional axe checks, but disables responsive device presets and browser locale simulation in both plans. Existing responsive/localized captures remain reviewable and exportable. Capture a page, compare versions, annotate issues, and choose which exports to share. SnapDiff does not upload your screenshots.
Coming soon — the Chrome Web Store listing is not available yet.
Coming soon — the Firefox Add-ons listing is not available yet.
Firefox 153+: limited features. Device presets and browser locale simulation are disabled in both plans. Existing captures remain reviewable and exportable.
What you can test on Free
| Capability | What it helps you review | What it does not do |
|---|---|---|
| Visual A/B testing | Compare two screenshots side by side and highlight pixel differences where available. | Run traffic-split experiments or calculate statistical significance. |
| Localization testing | Chromium only: simulate locale and language signals on a site that supports them. | Run in Firefox or automatically translate content. |
| Responsive testing | Chromium only: review layouts at different emulated viewport sizes. | Run presets in Firefox or validate physical devices or other browser engines. |
| Accessibility testing | Save an optional axe report with a capture. | Replace manual checks or certify WCAG compliance. |
| UI testing | Visually review page states, layouts, and annotations. | Run automated functional tests. |
Free is not unlimited. An A/B pair or a Multi group counts as one completed workflow. Annotation changes and downloads do not consume another workflow. See Free and Pro for allowance and watermark details.
Start with one workflow
- Choose the official Chrome or Firefox store when that browser's listing is available, then pin SnapDiff.
- Open a web page in desktop Chrome 120+ or Firefox 153+ and open SnapDiff.
- Choose Single, A/B, or Multi, then Viewport, Full page, or Area.
- Capture, review the result, and add drawing or text annotations.
- Download PNG, JPEG, or WebP, or return later through Captures.
Free requires no website account and includes full-quality exports with SnapDiff branding and capture timestamps. Chrome 120+ is the baseline. Edge, Brave, Opera, and Vivaldi support Chrome Web Store extensions, but general Chromium compatibility is not per-browser feature validation. Read Browser compatibility. The new Firefox 153+ implementation does not imply a published store listing or verified complete browser coverage. Mobile browser installs are not supported.
Pro purchase availability
See Free and Pro for purchase, license activation, and annual renewal details.
Find the right guide
Getting started
Choose the official Chrome or Firefox store, check feature limits, and make your first capture.
Capture and compare
Use A/B, pixel Diff, Multi, and Chromium-only device presets and language simulation.
Annotations and exports
Mark up images, choose an export format, and save reports.
Free and Pro
Understand workflow usage, watermarks, and the Pro subscription.
Privacy and local storage
Know what is saved and what to check before sharing.
Troubleshooting
Recover from capture errors, reload notices, and export limits.
What SnapDiff does not do
Device presets simulate responsive viewport sizes in Chrome, not other browser engines or physical devices. Language simulation is not automatic translation. Optional axe accessibility checks help find issues but do not certify accessibility compliance.
There is no SnapDiff cloud gallery, team account system, or Slack, Jira, or GitHub export integration. Downloaded images are yours to share deliberately. Read about sensitive page data and local storage before capturing private work.