HTTP 404 Not Found

What 404 means

Common causes

• A typo or an outdated link, including links from other sites to URLs you renamed without a redirect.
• Single-page apps: client-side routes like /dashboard/settings work while navigating but 404 on refresh, because the web server looks for a file at that path.
• Case sensitivity: /About and /about are different on Linux servers and S3, though they may both work on a case-insensitive Mac during development.
• Trailing slash mismatches (/docs/ vs /docs), especially on static hosting.
• A wrong path prefix behind a reverse proxy: in nginx, proxy_pass with or without a trailing slash changes the path the backend receives.
• APIs: a wrong version prefix, a record ID that doesn't exist, or an unsupported method. Express answers Cannot POST /x with 404 rather than 405.
• The deploy didn't include the file: wrong build output directory, or the file was ignored.
• A CDN serving a cached 404 from before the page existed.

How to fix a 404

curl -sI https://example.com/dashboard/settings
HTTP/2 404

curl -sI https://example.com/
HTTP/2 200

location / {
    root /var/www/app/dist;
    try_files $uri $uri/ /index.html;
}

location /assets/ {
    root /var/www/app/dist;
    try_files $uri =404;
}

# Request: GET /api/users

# Option A: backend receives /api/users
location /api/ {
    proxy_pass http://127.0.0.1:3000;
}

# Option B: backend receives /users
location /api/ {
    proxy_pass http://127.0.0.1:3000/;
}

app.use('/api', (req, res) => {
  res.status(404).json({ error: 'not_found', path: req.originalUrl });
});

import { notFound } from 'next/navigation';

const product = await getProduct(id);
if (!product) notFound();

Headers that matter with 404

Cache-Control

Give 404s a short max-age (or no-store) so a newly published page doesn't stay hidden behind a cached 404 on your CDN.

404 vs similar status codes

• 410 Gone: The resource existed and was removed deliberately. A clearer signal for clients and crawlers.
• 403 Forbidden: The resource exists but you may not have it. Servers sometimes answer 404 instead to hide it.
• 405 Method Not Allowed: The URL exists but not for that HTTP method.
• 301 Moved Permanently: If the content moved, redirect instead of returning a 404.

SEO impact of 404

404s don't hurt a site's rankings in general; Google expects them for URLs that never existed or were removed. What matters: return a real 404 status rather than a 200 "not found" page (soft 404); 301-redirect removed pages that have a clear replacement and valuable backlinks, but don't redirect everything to the homepage; use 410 if you want removal to read as intentional (Google treats 404 and 410 almost identically); and fix broken internal links, which waste crawl budget.

Related status codes

Looking for another code? Search the full HTTP status codes list, or read which code your API should return in the REST API status codes guide.

Learn more

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Frequently Asked Questions