Curbcut docs

Curbcut works the same way in Chrome, Edge and Firefox. These docs cover the browser extension; for the code editor, see Curbcut for VS Code.

Check a page

1. Open the page you want to test.
2. Click the Curbcut button in the toolbar, or press Alt+Shift+K. You can change the shortcut in the browser's extension shortcut settings.
3. Choose Check this page.

The popup shows the number of issues by impact and the first 20 issues. Open full report opens the full result in a new tab. The browser gives Curbcut access to that one tab only, after your click, and only until the tab goes to another page. To check again after you navigate, click the button again.

Read the report

The report groups issues by WCAG success criterion or by rule. Filter them by impact (critical, serious, moderate, minor) and by level. Each issue shows:

• the element's CSS selector and a piece of its markup;
• what is wrong and who is affected;
• the steps to fix it, often with a before and after example;
• a link to the W3C Understanding document for the criterion.

Buttons on each issue:

• Show on page: see below.
• Copy as Markdown: copies the issue for a bug ticket.
• Hide for this page: hides the issue on later checks of the same page.

Highlight issues on the page

Show on page switches to the checked tab, scrolls to the element and draws an outline with a numbered badge. The outline sits in a separate layer; the page's own content is not changed. Clear highlights in the popup removes everything Curbcut drew, and so does reloading the page. Highlighting works only while the browser's access to that tab lasts, so check the page again if you have navigated.

Structure view

The Structure tab of the report lists the page's headings from h1 to h6 and marks skipped levels. It also lists the landmark regions (header, navigation, main, footer and others). Each item has Show on page.

Contrast

For each contrast issue, the report shows the text and background colours as rendered, the measured ratio and the ratio WCAG requires for that text size and weight. It also suggests the nearest text colour that passes, with a copy button.

Options

Open the options page from the extension's menu in the toolbar, or from the browser's extension settings.

• WCAG level: A, AA (default) or AAA rules.
• Best-practice rules: include checks that are good practice but not WCAG requirements.
• Pro: activate, re-check or deactivate your license, and open the Polar customer portal.
• Delete data: removes all saved runs and settings.

Activate Pro

1. Buy Pro on the pricing page. Polar sends the license key by email.
2. Open the options page and choose Activate Pro.
3. Paste the key. The dialog tells you that the key and the label extension go to Polar (api.polar.sh) to verify the license, and nothing else.
4. Choose Activate. The browser asks for permission to contact api.polar.sh. Firefox also asks for your consent to send authentication information.

One key works on up to 5 activations across the extension and VS Code. Curbcut re-checks the key with Polar at most once every 7 days. If it cannot reach Polar, Pro keeps working for 14 days after the last successful check. Deactivate on the options page frees the activation and deletes the key from the browser.

Site scan (Pro)

1. Check a page of the site.
2. In the report, choose Scan site. The browser asks for access to that site only.
3. Curbcut reads the site's robots.txt and sitemap.xml. If there is no sitemap, it follows links on the checked page that stay on the same site.
4. It checks up to 500 pages, one at a time, in one inactive tab. It skips links that log out, add to a cart, delete something or change state in other ways. Choose Stop at any time.

The result lists issues per page and per rule. After the scan, Curbcut removes its access to the site unless you tick Keep access. Pages behind a login are checked only if you are signed in, the same as when you visit them.

Saved runs and comparison (Pro)

Site scans and Pro single-page runs are saved in the extension's own storage on your device. When you check the same site again, each issue is marked new, unchanged or fixed compared to the previous run. Delete saved runs on the options page.

Exports (Pro)

Export a run as CSV, JSON or a printable HTML report. To get a PDF, open the printable report and use the browser's Print and Save as PDF.

Private windows

In Firefox private windows, results stay in memory only. Nothing is written to storage, saving runs is turned off, and the highlight markers are removed when you clear them. In Chrome and Edge, the extension runs in incognito or InPrivate windows only if you allow it in the browser's extension settings.

Limits

Automated checks find only part of all WCAG failures. Test with a keyboard and a screen reader as well. Frames from other origins are not tested, and the report lists them. Curbcut does not change your pages and does not make a site compliant.

Help

Write to support@saffo.dev.