404Zen – Broken Link Fixer & Monitor

404Zen is a fast, private broken link checker — it runs on your server, respects your server, and never sends your data anywhere.

Broken links frustrate visitors and hurt your SEO. 404Zen scans every post and page for dead links, 404 errors, broken images and redirect chains, then lets you fix each one in seconds — without opening the post editor.

No cloud. No account.

All scanning happens on your own server. There is no scanning service, no account signup, no API key and no usage limits. Your content and your link data never leave your site.

Built to be light on your server

The #1 complaint about broken link checkers is server load. 404Zen was designed around that problem:

• Links are checked in small background batches (50 URLs per run by default) via WP-Cron.
• 404Zen watches your server load and automatically pauses scanning when the server is busy.
• It pauses between every request, uses lightweight HEAD requests where possible, and stops each run after a strict time budget.
• Pick your scan frequency — hourly, twice daily, daily or weekly.
• Batch size, request timeout and the load threshold are all configurable.

Find problems

• 404s and dead links — internal and external
• Broken images — missing files and dead hotlinks
• Timeouts and unreachable hosts
• Redirect chains — links that bounce through 2+ redirects before landing

Fix them in seconds

From one sortable dashboard you can:

• Edit a URL inline — the post content is updated for you
• Unlink — remove the link but keep the anchor text
• Dismiss — ignore false positives permanently
• Recheck — verify a fix immediately
• Use bulk actions to process many links at once

Stay informed

A weekly email digest (toggleable) summarizes newly found broken links, so you hear about problems even when you are not in the dashboard.

404Zen Pro

Need more? 404Zen Pro adds:

• Auto-redirect rules — send visitors from a broken URL to a working page automatically (301/302, applied only to requests that would 404)
• CSV export of all scan results
• Multisite support

Why 404Zen?

• Fast — batched, deduplicated URL checking; each URL is checked once per cycle no matter how many posts link to it.
• Private — a link scanner that needs a cloud account is a link scanner that ships your content off-site. 404Zen doesn’t.
• Respectful — scanning throttles itself and never competes with your visitors.

External services

404Zen makes two kinds of outbound HTTP requests, and nothing else:

1. Checking your own links. During a scan, your server requests each URL found in your content (via the WordPress HTTP API) to see whether it still works. These requests go to whatever sites your posts link to; they carry no personal data — only the URL being checked and a User-Agent header identifying the plugin and your site. This is the plugin’s core function and only happens when scans run.

2. Freemius (licensing and checkout). The plugin bundles the Freemius SDK, used solely for licensing, checkout and license management if you choose to upgrade to Pro. It runs in anonymous mode: no data is transmitted to Freemius on activation or during normal use — a connection is only made when you interact with the upgrade, checkout or license screens. See the Freemius Terms of Service and Freemius Privacy Policy.