About this tool
Review image exports before template releases so cross-origin images use the correct img crossorigin mode, expected ACAO/ACAC headers, and safe defaults for canvas-sensitive rendering flows.
Image Crossorigin Attribute Checker is useful when image requests, canvases, or CDNs depend on the correct `crossorigin` behavior. It helps teams review whether image tags are configured in a way that supports the intended fetch mode and avoids silent rendering or export problems.
- Parses rows in URL|image-url|crossorigin|acao|acac|status|context|bytes format and normalizes relative URLs with an optional base URL.
- Flags missing/invalid crossorigin attributes, anonymous/header mismatches, and use-credentials configurations that violate wildcard or ACAC requirements.
- Surfaces canvas-sensitive context risks plus per-page critical crossorigin-risk byte-budget overflow to prioritize the most impactful fixes.
How to use Image Crossorigin Checker
Enter the image markup or relevant attributes, review the checker output, and compare the result against the fetch and canvas behavior you expect. If the image is used in a canvas workflow, verify both the attribute and the server headers so the browser can actually honor the intended cross-origin setup.
When this tool is useful
- Review images used in canvas, WebGL, pixel reading, export, or screenshot workflows.
- Check third-party CDN images before adding them to templates that depend on CORS behavior.
- Audit markup after moving assets between origin storage, image CDNs, and signed delivery hosts.
Practical tips
- Match the `crossorigin` attribute to the actual use case instead of adding it to every image by default.
- Remember that `crossorigin="anonymous"` still requires compatible CORS response headers from the image host.
- Audit redirects separately because the final image response must preserve the expected CORS headers.
Examples you can test
These examples show the kind of real input and reviewed output this tool is designed to support. Use them as a starting point before pasting your own production content, then compare the output with the destination system that will use the result. The goal is not only to produce a value, but to make the input assumptions, output format, and review step clear enough that the result can be trusted in a real workflow.
Canvas export needs anonymous image CORS
Example input
<img src="https://cdn.example.com/chart.png" crossorigin="anonymous"> Response header: Access-Control-Allow-Origin: https://www.example.com Use case: draw image to canvas and export PNG
Expected output
Likely valid: the image requests anonymous CORS and the server allows the page origin. Canvas export should avoid a tainted canvas if the header is present on the final image response.
The attribute alone is not enough; the final image response must also include compatible CORS headers after redirects.
Missing attribute on a cross-origin canvas image
Example input
<img src="https://images.partner.example/photo.jpg"> Response header: Access-Control-Allow-Origin: * Use case: draw image to canvas and read pixels
Expected output
Warning: the server header allows CORS, but the image tag is missing crossorigin. Add crossorigin="anonymous" before using the image in a canvas read/export workflow.
Browsers decide the request mode from the element attribute, so a permissive server header does not automatically fix markup that requests the image without CORS.
Validation checklist
Run through these checks before copying the result into a CMS, codebase, spreadsheet, campaign, support ticket, or production document. Small formatting differences, unit assumptions, hidden whitespace, and platform-specific rules are common sources of mistakes in quick browser tools, so the final review should happen in the same context where the output will be used.
- Identify whether each image is only displayed or also used in canvas, WebGL, pixel reading, or export flows.
- Use `crossorigin="anonymous"` only when the image host sends compatible Access-Control-Allow-Origin headers.
- Verify redirects preserve CORS headers on the final image response, not only on the first URL.
- Avoid `use-credentials` unless cookies or credentials are intentionally required and the server is configured for credentialed CORS.
Why people use this tool
People search for image CORS-related checks when a front-end integration is already failing or behaving inconsistently. The page is strongest when it turns a vague browser issue into a clearer attribute-level diagnosis.
Related search intents
image crossorigin checker, img crossorigin attribute, image cors attribute audit, crossorigin image tag checker, canvas image cors check.