Site migration checklist: how to make sure every old URL still lands somewhere (301s, chains, 404s, hreflang)

Mauberme — Fri, 06 Nov 2026 08:28:25 +0000

Most traffic losses after a domain or URL change are not caused by Google. They come from redirects that are missing, chained or pointing to the wrong page. The checklist we use:

Build the redirect map before launch: one row per old URL → new URL. Export old URLs from the sitemap, analytics and backlinks, not only from the CMS.
One hop only. old → new, never old → intermediate → new. Each extra hop is slower and risks losing ranking.
301, not 302, for permanent moves.
Right destination, not just "a 200". Sending everything to the homepage counts as a soft 404.
No loops and no redirects to pages that return 404 or 500.
hreflang: if the site is multilingual, the language versions must point to each other.
Check again after launch with the real server, CDN and trailing-slash rules in place.

Doing step 7 by hand with a spreadsheet and curl -I is fine for 20 URLs, but painful for 2,000. I packaged the checks we used to migrate a multilingual site (3 legacy domains, 89 redirects, 4 languages) into a tool. You paste the old,new list and it opens every old URL, follows the redirects and gives you a 0–100 report with every broken row. It can also generate the redirect rules for Next.js, Vercel, Netlify, nginx, Apache or Cloudflare: https://apify.com/mauberme/site-migration-auditor (free during launch).

What's the worst migration mistake you've had to clean up?

Your hero video is probably 10x heavier than it needs to be (and how to fix it without installing ffmpeg)

Mauberme — Fri, 06 Nov 2026 08:27:06 +0000

Background videos and product clips are often the heaviest thing on a landing page. A 40 MB phone recording uploaded "as is" hurts LCP, burns mobile data and often won't start until most of it has downloaded.

Three things make a video web-ready:

The right size. Nobody needs 4K in a 1200 px wide hero. 720p or 1080p is plenty, and 360–480p works for small embeds.
A web-friendly codec. H.264 MP4 plays everywhere. WebM (VP9) is usually smaller, so offer both with <source> tags and let the browser pick.
Fast start. By default, MP4 files store their index (the moov atom) at the end, so the browser has to download everything before playing. Moving it to the front (-movflags +faststart) lets playback start immediately.

With ffmpeg that is roughly:

ffmpeg -i input.mov -vf "scale='min(1280,iw)':-2" -c:v libx264 -crf 26 -preset slow \
  -movflags +faststart -an output.mp4

Then add a poster image so something shows before the first frame loads:

<video autoplay muted loop playsinline poster="poster.jpg">
  <source src="hero.webm" type="video/webm">
  <source src="hero.mp4" type="video/mp4">
</video>

If you don't want to deal with ffmpeg, or you need to do this for many videos or from an automation: I built a small cloud tool that does exactly these steps. You paste video links and get back a fast-start MP4, an optional WebM and a poster image. It never makes a video bigger than the original. It runs on Apify and is free during launch: https://apify.com/mauberme/video-for-web

It can also be called from an API or from an AI agent through Apify's MCP server, which helps if you process videos inside a pipeline.

What's the heaviest video you've shipped by accident? 🙂

DEV Community: Mauberme

Site migration checklist: how to make sure every old URL still lands somewhere (301s, chains, 404s, hreflang)

Your hero video is probably 10x heavier than it needs to be (and how to fix it without installing ffmpeg)