BadlinkCheck browser extension
Open your website, click the BadlinkCheck icon and start the check. The extension crawls the whole site from your browser and finds 404 pages, server errors, timeouts, broken images and redirects.
Get the extension – free Version 1.0.0Choose your browser
The extensions are being published in the Chrome Web Store, Edge Add-ons, Firefox Add-ons and the App Store. Until then you can install the package manually – see the guide below.
How it works
Available for Chrome, Chromium, Edge, Firefox and Safari.
Click the BadlinkCheck icon in the toolbar and choose “Check this website”. You can also enter any start URL.
It follows links within the website (and its sitemap), checks every link, image, script and stylesheet and reports 404, 5xx, timeouts and redirects.
Found errors and the list of checked pages are stored in your browser. If you connect your BadlinkCheck account, the report is also saved under Reports.
Why an extension?
Instant, no queue
The check starts immediately and you watch the progress live.
Works behind login & firewalls
Checks staging servers, intranets and members-only areas you can open in your browser.
No bot blocking
Requests come from your own browser, so Cloudflare and similar protections block them far less often.
Private by design
Page content never leaves your computer. Only errors and checked URLs are stored – and sent to us only if you want.
Manual installation
Chrome, Chromium, Brave, Opera
- Download the package and unzip it into a folder you will keep.
- Open
chrome://extensionsand switch on “Developer mode” (top right). - Click “Load unpacked” and select the unzipped folder.
- Pin the BadlinkCheck icon to the toolbar using the puzzle icon.
Microsoft Edge
- Download the package and unzip it into a folder you will keep.
- Open
edge://extensionsand switch on “Developer mode” (left panel). - Click “Load unpacked” and select the unzipped folder.
- Pin the BadlinkCheck icon to the toolbar using the puzzle icon.
Mozilla Firefox
- Download the .xpi file.
- Open
about:debugging#/runtime/this-firefoxand click “Load Temporary Add-on…”. - Select the downloaded .xpi file. A temporary add-on stays until Firefox restarts – the permanent version will be available on addons.mozilla.org.
Apple Safari (macOS)
- Safari extensions are distributed through the App Store. Until it is published, developers can build it with Xcode:
- Download and unzip the source package, then run
xcrun safari-web-extension-converter <folder>. - Run the generated project in Xcode, then enable BadlinkCheck in Safari → Settings → Extensions and allow it on all websites.
What data is stored
- Pages are downloaded and analysed only in your browser. Their content (HTML) is never stored or sent anywhere.
- The extension keeps the last 100 checks in the browser’s local database: start URL, checked page URLs with status codes and found errors. You can export them as JSON or CSV, or delete them.
- If you connect your account, the same summary is sent to BadlinkCheck.com and shown under Reports. You can disconnect a browser at any time.
Frequently asked questions
What happened to the automatic server checks?
They have been stopped. All link checks now run in the browser extension, which is faster, works on protected sites and is not blocked as a bot.
Do I need an account?
No. The extension works on its own. An account lets you keep reports online and access them from any device.
Can I close the tab during the check?
Keep the check tab open until it finishes. You can use other tabs meanwhile. Partial results are saved continuously.
Will the check overload my server?
By default the extension sends at most 4 parallel requests with a short pause. You can lower the speed in the check options.