Key takeaways
- A redirect sends people and Google from an old URL to a new one automatically.
- Use a permanent redirect (301 or 308) when a page has moved for good, a temporary one (302 or 307) when it will come back.
- A 404 is normal for pages that no longer exist. It becomes a problem when it hits pages with links, traffic or internal links.
- A canonical tag is a hint about the preferred URL; a redirect is an instruction.
Redirects are one of the most common fixes in my technical SEO work. They look simple, but a few wrong choices during a redesign can cost months of traffic.
What is a redirect?
A redirect is an instruction on the server that says a URL now lives somewhere else. When a browser or Google asks for the old address, the server answers with a status code and the new address, and the visitor lands on the new page automatically. Done right, it keeps visitors, links and rankings moving to the new page.
When should you use a 301 or a 302?
Use a permanent redirect, 301 or 308, when a page has moved for good: a new URL, a merged page, a new domain. Use a temporary one, 302 or 307, only when the original page will come back soon. Google treats a permanent redirect as a strong sign that the new URL should be the one shown in results.
| Code | Type | What Google shows |
|---|---|---|
| 301, 308 | Permanent | The new URL |
| 302, 303, 307 | Temporary | Usually the original URL |
| Meta refresh, instant | Treated as permanent | The new URL |
| JavaScript redirect | Last resort | Depends on rendering working |
That table summarizes Google's own page on redirects and Google Search, which recommends server-side redirects whenever possible and JavaScript redirects only when nothing else is available.
Is a 404 error bad for SEO?
Not by itself. A 404 tells Google a page does not exist, which is the honest answer for content you removed with no replacement. It becomes a problem when the missing page had backlinks, traffic or links from your own menus, because that value and those visitors hit a dead end.
Google's page on HTTP status codes explains how it treats 404 and 410 responses: the URL is eventually dropped from the index. That is fine for pages you want gone. For removing a page on purpose, see how to remove a page from Google.
How to fix 404 errors step by step
- Open the Page indexing report in Search Console and export the URLs marked "Not found (404)".
- Sort them: pages with backlinks or past traffic first, typos and junk URLs last.
- Redirect each valuable URL to the closest equivalent page, not to the home page.
- Fix internal links that still point to the old URL, so the redirect is a safety net, not a crutch.
- Leave the rest as 404 or 410. Not every missing URL needs a redirect.
- Check a sample with the URL Inspection tool after the change.
The Page indexing report lists these URLs. Avoid chains: an old URL should go straight to the final page, not through two or three hops.
What is the difference between a redirect and a canonical tag?
A redirect moves people and Google to another URL; the old page is no longer visible. A canonical tag keeps both pages visible to people but tells Google which one you prefer in results. Use redirects when a page is gone for good, canonicals when similar pages must stay live, such as product variants.
Google calls choosing the preferred URL canonicalization and explains the options in how to specify a canonical URL.
Redirects during a redesign
A redesign or domain change is where most redirect mistakes happen. Make a map of every old URL and its new home before launch, test it and keep the redirects in place for the long term. Google's site move guide and my guide to a website redesign without losing SEO walk through it. The technical SEO checklist covers the rest. As an SEO consultant, I review redirect maps before launch: book a free diagnosis.
Frequently asked questions
How long should I keep a 301 redirect?
As long as possible. Removing it later breaks old links and bookmarks.
Should I redirect all 404s to the home page?
No. Send each one to its closest equivalent, or let it stay 404 if nothing matches.
Is a 410 better than a 404?
Both tell Google the page is gone. A 410 says so more explicitly; either works.
Do redirects slow my site?
One redirect is barely noticeable. Chains of several hops add delay and should be fixed.
Can too many 404s get my site penalized?
No. 404s for pages that do not exist are normal. Fix the ones that lose links or traffic.
About the author
Juan José Giraldo is an SEO consultant in Medellín, Colombia, with 5+ years of experience. He works on technical and local SEO for 600+ US car dealerships at Reunion Marketing, an Inc. 5000 agency, and supervises the SEO of 18 US online stores with more than 3 million products at Prontomowers. Read more · LinkedIn.
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