Engineering service
Browser & Extension QA and Testing
We test your extension across real browser versions, update paths, and managed environments to catch the bugs that only show up outside your own dev setup.
- 15+ years of experience
- 300+ projects delivered
- Clients worldwide
- NDA available
Overview
What this is, and when it is the right call
Extensions run in environments you do not control: many browser versions, strict sites, managed profiles and long-lived sessions. Most problems appear at the edges, such as a service worker that stopped while idle or an update that changed permissions.
We test for compatibility, regression and performance, and we report every issue with steps to reproduce it. Security review is a separate service; this page covers functional and performance quality.
Who this is for
- Teams shipping a browser extension to more than one browser or to enterprise customers.
- Products that see bug reports that only occur on certain sites, browser versions or managed setups.
- Teams preparing a major release or a move to Manifest V3 and wanting an independent check.
- Companies that maintain a custom browser build and need it tested, not only extensions.
How it works
The QA cycle
Each release repeats this cycle, and the regression suite grows with every confirmed bug.
Test plan
Agree the browsers, versions, sites and user journeys that matter for your product.
You get: A written test plan
Matrix run
Run the plan across browsers and channels, mixing scripted checks with exploratory testing.
You get: Results per browser and version
Report with reproduction
Log each issue with exact steps, environment and evidence, so a developer can reproduce it quickly.
You get: Actionable bug reports
Fix verification
Retest each fix on the environments where the bug appeared.
You get: Confirmed fixes or reopened issues
Regression suite
Turn confirmed bugs into repeatable checks, automated where that pays off.
You get: A suite that runs on future releases
What we offer
What we engineer: Browser & Extension QA and Testing
Cross-Browser Compatibility Testing
Run the same user flows on Chrome, Edge, Firefox, Brave, and Safari, and flag behavior that only breaks on one engine.
Beta & Dev Channel Coverage
Test against upcoming browser builds so an engine change surfaces before it reaches your users on the stable channel.
Performance & Memory Profiling
Measure startup time, idle memory growth, and background CPU draw across sessions that run for hours, not minutes.
Update & Migration Testing
Confirm an installed extension updates cleanly, keeps its stored data, and carries settings forward between versions.
Enterprise & Managed Profile Testing
Check behavior under group-policy pushes, forced settings, and locked-down corporate proxies.
Regression Suite Development
Turn every confirmed bug into an automated check that runs against the next release, so it cannot slip through twice.
Deliverables
What you get
- 01
Test plan and matrix
The browsers, versions, sites and scenarios we cover, agreed with you before testing starts.
- 02
Bug reports
Each issue written up with reproduction steps, environment details and screenshots or recordings where useful.
- 03
Compatibility findings
A summary of what works and fails on each browser and version tested.
- 04
Performance observations
Startup, memory and background CPU findings from long-running sessions.
- 05
Fix verification
Retesting of fixes, with results reported against the original issue.
- 06
Automated regression tests
Scripted tests for the flows where automation is reliable enough to justify the upkeep.
Compare
What we test
The exact scope is set in the test plan. These are the dimensions we usually cover.
| Dimension | What we check |
|---|---|
| Browsers and versions | Current stable and beta channels, plus the older versions you commit to supporting. |
| Service worker lifecycle | State after the worker stops when idle, wake-up on events and alarms behaving as expected. |
| Permissions and installs | Fresh installs, updates that add permissions and the handling of optional permissions. |
| Sites | Pages with strict CSP, iframes, single-page apps, PDF viewers and shadow DOM. |
| Managed environments | Policy-installed extensions, enterprise proxies and restricted profiles. |
| Performance | Startup cost, memory over long sessions and CPU use while idle in the background. |
| Upgrades | Moving from the previous version to the new one, including data migration. |
Why it matters
What this gives you
Bugs Your Developers Can Reproduce
Every report includes the exact browser, version, and steps that trigger it, so fixing starts immediately instead of after a repro hunt.
A Regression Suite That Grows Over Time
Each release adds to a suite built from real bugs found in your product, not a generic checklist written before we saw it.
Managed Environments Tested Before Customers Find Them
Enterprise policies and locked-down profiles get checked here first, before a customer's IT department reports the problem.
One Team for the Browser and the Extension
When you ship a custom browser and an extension together, we test the points where they interact, not just each piece on its own.
Our approach
How an engagement runs
Scope and access
You share a build or store link, test accounts and your priorities, and we agree what is in scope.
You get: An agreed scope
Explore
We use the extension as your users do, to find where it breaks before writing formal cases.
You get: Early findings and risk areas
Test and report
We run the test plan and send reports as issues are found, not only at the end.
You get: Reproducible bug reports
Verify and hand back
We verify fixes and hand over the test assets, including any automated tests.
You get: A results summary and test assets
When this is not the right fit
A few cases where this approach may not be the best choice for you.
- A vulnerability-focused assessment. That is the extension security audit, which is a separate service.
- A product with no stable build yet. Testing an unfinished build mostly reports what the team already knows.
Tech stack
Technologies we use
The engines, APIs and tools behind our browser & extension qa and testing work.
Chrome DevTools Protocol
Firefox DevToolsGroup Policy (ADMX)FAQ
Questions engineers ask before starting
Chrome, Edge, Firefox, Brave and Safari, chosen to match where your users are. We can include beta channels so problems surface before a release reaches your users.
Our services
Related services
Explore more services that work alongside this one.
Talk to a Browser Engineer
Ship Browser Software With Confidence
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