Crossbrowsertesting.com Screenshot Comparisons API
★ Only Publicly Available OpenAPI DocumentDeveloper ToolsTesting Qabasic3 EndpointsREST
For Agents
Compare CrossBrowserTesting screenshot test runs against a baseline or prior version to surface layout differences and a hosted review UI link.
Use for: I need to compare two screenshot test versions for visual regressions, Find layout differences between Chrome and Firefox screenshots in a test, Get the Comparison UI link for a screenshot diff, Check whether the latest test run differs from yesterday's baseline
Not supported: Does not handle test execution, browser session orchestration, or screenshot capture - use for comparing already-captured CrossBrowserTesting screenshots only.
The CrossBrowserTesting Screenshot Comparisons API exposes pixel-level layout-difference detection between captured browser screenshots, designed to plug visual-regression checks into automated test pipelines. Engineering teams use it to compare a target screenshot test against a baseline, a previous version, or a single browser, and surface a hosted Comparison UI link so reviewers can inspect highlighted differences. The three endpoints all return both a structured diff result and a UI link for human review.
Install Jentic One Beta
Connect the Crossbrowsertesting.com Screenshot Comparisons API to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Crossbrowsertesting.com Screenshot Comparisons API, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.
Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.
1
Step 1: Jentic One Host machine
# On the machine that will host your Jentic One instance:
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fcrossbrowsertesting.com%2Fcrossbrowsertesting-screenshot-comparisons" | sh2
Step 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fcrossbrowsertesting.com%2Fcrossbrowsertesting-screenshot-comparisons" | sh
jentic register # connects your agent to your Jentic One instanceJentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.
Capabilities
What an agent can do with Crossbrowsertesting.com Screenshot Comparisons API.
Compare a full screenshot test run across browsers against a single baseline browser
Compare two screenshot test versions to detect layout regressions between releases
Compare a single browser screenshot against another single browser screenshot
Retrieve a hosted Comparison UI link for visual review of detected differences
Plug visual-regression checks into CI/CD pipelines via basic-auth REST calls
Use Cases
Patterns agents use Crossbrowsertesting.com Screenshot Comparisons API for, with concrete tasks.
★ Visual Regression in CI
Block a deploy when the rendered UI changes unexpectedly by comparing the current screenshot test version against the previous one in CI. The pipeline calls GET /screenshots/{target_screenshot_test_id}/{target_version_id}/comparison/parallel/{base_version_id} after each test run, parses the diff response, and fails the build if changes appear in protected pages. Reviewers open the returned Comparison UI link to inspect the highlighted regions.
Compare screenshot test version v42 against baseline version v41 and fail the build if any layout differences are detected
Cross-Browser Layout Audit
Confirm that a page renders consistently across all supported browsers by comparing every browser's screenshot in a test against a single baseline browser. The team calls GET /screenshots/{target_screenshot_test_id}/{target_version_id}/comparison/{base_result_id} with the baseline result ID, then surfaces the diff metrics per browser. This is a faster check than human eyeballing for catching browser-specific layout bugs.
Compare every browser in screenshot test 88 against the Chrome 120 baseline result and report which browsers have layout deltas
Single-Screenshot Targeted Comparison
Drill into a specific failing screenshot by comparing two individual results - useful when a regression is suspected on one browser/page combination and a full-test diff is overkill. The agent or developer hits /screenshots/{target_screenshot_test_id}/{target_version_id}/{target_result_id}/comparison/{base_result_id} and reviews the returned UI link.
Compare result 9001 in test 42 version v3 against baseline result 8999 to confirm the visual fix landed
AI Agent Visual QA Reporting
An AI agent embedded in a release pipeline pulls visual-diff data from CrossBrowserTesting through Jentic and writes a release-ready summary. The agent searches for the crossbrowsertesting_compare_versions operation, executes against the customer's vaulted basic-auth credential, and renders a markdown report linking back to the Comparison UI for any browsers with detected differences.
Use the Jentic SDK to compare the latest screenshot test version against the previous one and produce a markdown summary of layout differences
Key Endpoints
3 endpoints — the crossbrowsertesting screenshot comparisons api exposes pixel-level layout-difference detection between captured browser screenshots, designed to plug visual-regression checks into automated test pipelines.
METHOD
PATH
DESCRIPTION
GET
/screenshots/{target_screenshot_test_id}/{target_version_id}/comparison/parallel/{base_version_id}
Compare two screenshot test versions
GET
/screenshots/{target_screenshot_test_id}/{target_version_id}/comparison/{base_result_id}
Compare a full screenshot test against a baseline result
GET
/screenshots/{target_screenshot_test_id}/{target_version_id}/{target_result_id}/comparison/{base_result_id}
Compare a single screenshot result against a baseline result
GET
/screenshots/{target_screenshot_test_id}/{target_version_id}/comparison/parallel/{base_version_id}
Compare two screenshot test versions
GET
/screenshots/{target_screenshot_test_id}/{target_version_id}/comparison/{base_result_id}
Compare a full screenshot test against a baseline result
GET
/screenshots/{target_screenshot_test_id}/{target_version_id}/{target_result_id}/comparison/{base_result_id}
Compare a single screenshot result against a baseline result
Why Jentic?
What agents get from Jentic-routed access to this vendor.
Setup
Wiring CrossBrowserTesting screenshot comparisons by hand means encoding its username and authkey for Basic auth and threading the test, version, and result ids through each comparison call. Through Jentic you install once, import CrossBrowserTesting from the API Directory, store the credentials once, and your agent calls it.
Permission scoping
The comparison endpoints are all read-only lookups that carry the screenshot test and version ids in the URL path, so scope the agent to the comparison operations it needs. It reads comparisons only and runs nothing you have not allowed.
Credential isolation
Your CrossBrowserTesting username and authkey are stored once, encrypted, by your own Jentic One instance and applied as the Authorization header at execution time. They never enter the agent's prompt, logs, or context.
Intent-based discovery
Agents search Jentic by intent such as 'compare screenshot test versions', and Jentic returns the matching CrossBrowserTesting operation with its input schema so the agent calls the right endpoint without browsing the reference docs.
Related APIs
Alternatives and complements available in the Jentic catalogue.
FAQs
Specific to using Crossbrowsertesting.com Screenshot Comparisons API through Jentic.
What authentication does the CrossBrowserTesting Screenshot Comparisons API use?
The API uses HTTP Basic Authentication - the username and authkey from your CrossBrowserTesting account are sent in the Authorization header. Through Jentic, both values are stored encrypted in the vault and injected at request time so they never enter the agent's context.
Can I compare two specific screenshot test versions?
Yes. Call GET /screenshots/{target_screenshot_test_id}/{target_version_id}/comparison/parallel/{base_version_id} with the IDs of the target and base versions to get the structured diff and a Comparison UI link.
How do I run a visual regression check through Jentic?
Search Jentic for 'compare screenshot test versions', load the operation schema, and execute with the test ID, target version, and base version. The Jentic SDK handles basic-auth header injection so the agent never holds the credentials.
Does the API return a UI link or just diff data?
All three comparison endpoints return both structured diff data and a link to the hosted Comparison UI, so you can fail a build automatically and still hand reviewers a visual representation of the differences.
How many endpoints does this API expose?
Three endpoints, all under /screenshots/{target_screenshot_test_id}/..., covering version-to-version, full-test-to-baseline, and single-result-to-single-result comparisons.
Can I compare an individual screenshot result rather than a whole test?
Yes. GET /screenshots/{target_screenshot_test_id}/{target_version_id}/{target_result_id}/comparison/{base_result_id} compares a single target result against a single base result, which is useful for narrowly targeted regression confirmation.
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