Q: After a relaunch we had 1,800 pages 404-ing — how much traffic did fixing them bring back?

Q: After a relaunch we had 1,800 pages 404-ing — how much traffic did fixing them bring back?

Don't panic, this is the most fixable migration problem there is.

Short answer: most of it, and quickly.

Long answer: a relaunch dropped old URLs without redirects — 1,800 pages went 404. Organic traffic fell 34% in 10 days. We pulled the top 404s from GSC and server logs, ranked by old impressions, and mapped the top 600 (which covered ~90% of lost traffic) to the closest live equivalent with 301s. The long tail got redirected to relevant category pages, not the homepage.

Traffic recovered 28 of the 34 points within 5 weeks. We never reached 100% because some content genuinely no longer existed — and that's fine.

Next step: sort your 404s by lost clicks, fix the top 20% first, and don't lazy-redirect everything to the homepage.