Screenshot testing: a method for detecting visual regressions that consists of capturing an image of a web page or component, then comparing it with a reference image, with differences judged significant being flagged as potential regressions.
Percy was for a long time the name that came first when people talked about automated visual testing. Acquired by BrowserStack in 2020, the tool established itself as the "obvious" solution for teams wanting to add a layer of visual comparison to their test pipeline.
The landscape has changed. And the question every team should ask today is no longer "how do we integrate Percy into our tests?" but "is Percy's approach the most relevant one for our need?"
Delta-QA answers the same problem differently. No per-screenshot bill, no tests to write: you record your journeys in the browser, and Delta-QA tells you which element changed from one version to the next. As SaaS or, with the On-Premise offer, inside your network. Let's compare the two.
All our comparisons, based on verifiable criteria: Alternatives and comparisons.
What if testing every page didn't raise your per-screenshot bill? Delta-QA verifies your journeys without code, with a free account and no credit card. Try Delta-QA for free →
Percy: Visual Testing as an Extension of Your Existing Tests
Percy works on a simple principle: at chosen points in your automated tests, you trigger a capture. This capture is sent to BrowserStack's infrastructure, where it is compared with a reference image (the baseline). The differences are displayed in a web dashboard where your team approves or rejects each change.
To use it on your journeys, you must first have automated tests (Cypress, Playwright, Selenium, Storybook, or one of the many supported frameworks). You install the matching Percy SDK, add capture calls at the relevant places, and configure a token to communicate with Percy. BrowserStack announces a "Visual Test Integration Agent", still upcoming as of 10/2026, to automate this setup from the IDE.
Percy also offers a Website Scanner: you add pages through their sitemap and schedule recurring scans, including on a pre-production environment and behind authentication. It's an entry point with no tests to write, for monitoring pages. Journeys (login, cart, multi-step form), on the other hand, go through your tests and the SDK.
If you are a developer comfortable with testing tools, all of this is doable in a few hours. If you are not a developer, you depend on someone else to set up and maintain the tests for your journeys.
Delta-QA: Visual Testing as a Standalone Activity
Delta-QA starts from the opposite premise: visual testing shouldn't be a graft onto your functional tests. It is an activity in its own right, with its own users.
Concretely, you open your site in Delta-QA and walk through the scenario like a user: login, navigation, form. Each step becomes a checkpoint. On the next version, Delta-QA replays the journey in a real browser and compares each page with its reference the way a human eye would: it spots the elements that changed and names them in the report.
The result is a readable report: an element added, removed, modified, or moved, a color that changed, a margin that moved, a font that differs. You judge each difference, intended or bug, and the reference moves forward with you.
And all this without writing a single line of code. If you know how to browse your site, you know how to record a scenario.
Code vs No-Code: Why It Changes Everything
The most fundamental difference between Percy and Delta-QA is not technical, it's organizational.
Percy is first and foremost a developer tool. For journeys, it lives in the code, is installed via npm or pip, is configured in files, and runs in CI/CD pipelines. It's perfectly logical when your testers are developers.
Think about your team. Who cares about the visual quality of your product? Developers, certainly. But also the designers who created the mockups, the product owners who validated the journeys, the QA managers who define the acceptance criteria, the marketing managers who run the content pages.
With Percy, these profiles approve or reject changes in the dashboard, and can add pages to the Website Scanner. But a journey that requires actions (logging in, filling a cart, submitting a form) remains the business of those who write the tests.
Delta-QA includes them. Anyone on the team can record a journey, replay it, and judge the results. Visual testing becomes a shared responsibility instead of a delegated technical task.
The Per-Screenshot Bill: A Model That Weighs on Coverage
Percy's business model deserves particular attention, because it directly ties test coverage to budget.
As of 10/2026, according to BrowserStack's pricing grid:
- Free: 5,000 screenshots per month, unlimited users, one month of history.
- Desktop: from $199 per month billed annually, for 10,000 screenshots per month; each additional screenshot is billed $0.036.
- Desktop & Mobile: from $599 per month billed annually, for 25,000 screenshots per month and real mobile devices; $0.048 per additional screenshot.
- Enterprise: optional, quote-based (SSO, access control, SLA).
The point to watch is the definition of a screenshot: each combination of page, browser, and screen width produces one. If you test 10 pages at 3 widths and 2 browsers, that's 60 screenshots per run. At two runs a day, the free quota is used up in under three weeks.
Take an e-commerce site with 500 product pages, checked after every daily deployment at three screen widths: 45,000 screenshots per month. That's beyond the base Desktop plan, and every extra screenshot is paid for.
This model creates a tension between test coverage and budget. Teams end up limiting the pages tested, the frequency, or the screen widths, not because it's the right technical decision, but because the budget imposes it.
Delta-QA doesn't bill per screenshot. The free account is created without a credit card, then the plans follow usage, with no counter per capture, browser, or screen width.
Cloud or On-Premise: Sovereignty of Your Data
Every screenshot sent to Percy goes through BrowserStack's infrastructure and is stored there. For most public sites, that's not a problem. But public sites are only a fraction of what teams test.
What about your back-office? Your internal dashboard with customer data? Your pre-production environment with poorly anonymized production data? Your medical portal, your banking interface, your HR system?
Sending captures of these pages to a third party, even a certified one, raises questions that some organizations cannot ignore: GDPR, HDS, PCI-DSS, internal security policies. As of 10/2026, Percy's grid does not offer on-premise deployment.
Delta-QA answers with its On-Premise offer. The tool runs inside your network, your pages are compared there, and the results stay there. The offer can be evaluated with a free one-month POC.
Your captures must not leave your premises? Delta-QA runs as SaaS or, with the On-Premise offer, inside your network. Start with a free account, no credit card. Try Delta-QA for free →
Result Stability: Rendering Noise
Anyone who has used a screenshot-based visual testing tool knows false positives. Font rendering varies from one system to another, anti-aliasing differs, an animation captured at a different moment produces another image, a scrollbar that appears shifts everything by a few pixels.
Percy has worked a lot on this point. Its "Percy Visual Engine" relies, according to BrowserStack, on computer vision and machine learning for diffs. Percy disables animations and GIFs before capture, and offers a comparison sensitivity setting. The "Visual Review Agent" highlights significant changes to speed up review. These tools reduce triage, without eliminating it: someone still has to look at each diff and decide.
Delta-QA takes the problem from the other end: it compares the elements of the page, not two images. The report says which element changed and how (color, margin, font, position), which makes each difference quick to judge. To understand the difference between the two approaches, see our article on pixel-by-pixel vs perceptual comparison.
CI/CD Integration: Two Approaches
Percy integrates into CI/CD pipelines through its SDK. It's a mature integration that works with the major CI systems (GitHub Actions, GitLab CI, Jenkins, CircleCI), with a status directly in the pull request.
Delta-QA now has an SDK, Vision, for Playwright (TypeScript/JavaScript). With the Vision SDK, a Playwright test adds one line where a page must be checked; an unreviewed difference makes the test fail, and the CI log gives the link to the report. Your coded tests and your scenarios recorded without code live in the same space: same references, same report. Percy keeps the advantage of maturity and the number of frameworks covered.
When Percy Remains the Right Choice
You want visual testing as a complement to your existing functional tests. If you already have a robust Cypress, Selenium, or Playwright suite, adding Percy is the path of least resistance, with mature CI integration across many frameworks.
You need visual cross-browser testing. Percy captures on several browsers through BrowserStack's infrastructure, and on real mobile devices with the Desktop & Mobile plan. Delta-QA currently compares on Chromium; Firefox and WebKit are planned.
Your team is made up of developers. If the only people who will do visual testing are comfortable with SDKs and pipelines, Percy's barrier to entry is low.
When Delta-QA Is the Best Option
Visual testing is a need in itself, not an extension of your functional tests. If you have no automated tests, or if your journeys aren't covered by them, Delta-QA verifies them without writing any.
Non-developers must take part. QA, designers, product owners, marketing: if they must record and judge journeys without going through a developer, Delta-QA is made for them.
You refuse per-screenshot billing. If you don't want the number of pages, browsers, and screen widths tested to be dictated by a counter, Delta-QA's model removes that constraint.
Data confidentiality is non-negotiable. If your policies forbid sending captures to a third party, Delta-QA's On-Premise offer keeps everything in your network.
You want a report you can read. If sorting through image diffs has discouraged you, a report that names the changed element and the modified property changes the review.
The Verdict
Percy is a mature tool, well integrated into the BrowserStack ecosystem, and effective for teams of developers who want to add a visual layer to their automated tests, with cross-browser and real devices.
But many teams don't need an SDK, a cloud service, and per-screenshot billing to detect the visual regressions of their journeys. They need a tool the whole team can use, and whose bill doesn't grow with the rigor of the tests.
Delta-QA is designed for them. It isn't broader than Percy, and doesn't claim to be. It solves visual testing of journeys with less friction and more accessibility. And the tool that gets adopted by the whole team is often more useful than the one that impresses.
Ready to test your journeys without counting your screenshots? Record your first scenario with Delta-QA, with a free account and no credit card. Try Delta-QA for free →
FAQ
Is Percy free?
Percy offers a free plan of 5,000 screenshots per month, with unlimited users and one month of history (as of 10/2026). Beyond that, paid plans start at $199 per month billed annually for 10,000 screenshots per month, then each additional screenshot is billed. Delta-QA starts with a free account, no credit card.
Can Percy be used without writing code?
Partly. Percy's Website Scanner monitors pages added through a sitemap, with scheduled scans, without any test to write. To verify journeys (login, cart, form), you need automated tests and the Percy SDK. Delta-QA records these journeys without code, from the browser.
Does Delta-QA detect the same bugs as screenshots?
It detects regressions that affect the page's elements: colors, sizes, positions, fonts, margins, added or missing elements. The internal content of an image or a rendering defect specific to one browser falls more under an image comparison. Delta-QA currently compares on Chromium.
Does Percy handle pages with authentication?
Yes. In your automated tests, the script handles login before the capture; the Website Scanner can also scan pages behind authentication. With Delta-QA, login is simply part of the recorded scenario.
Does Delta-QA have an SDK like Percy?
Yes. Delta-QA now has an SDK, Vision, for Playwright (TypeScript/JavaScript). The Vision SDK has Delta-QA check a page in one line, and an unreviewed difference makes the test fail with the report link in the CI.
Can Percy run on-premise?
As of 10/2026, Percy's grid does not offer on-premise deployment: rendering and storage happen on BrowserStack's infrastructure. Delta-QA offers an On-Premise offer, which can be evaluated with a free one-month POC.
Can Percy and Delta-QA coexist?
Yes. You can keep Percy in your automated tests for components and cross-browser, and use Delta-QA so the whole team verifies its journeys without code. The two tools are independent.