What does 413 Request Entity Too Large mean in WordPress?

The web server in front of WordPress, usually Nginx, refused the upload because it is bigger than its own size limit. WordPress and PHP never saw the file, so raising only the PHP or WordPress upload limit does not fix it.

How do I fix 413 Request Entity Too Large on Nginx?

Add client_max_body_size 64M; to the http or server block, test the config with nginx -t and reload Nginx. On shared or managed hosting, ask support to raise client_max_body_size together with PHP's upload_max_filesize and post_max_size.

Why does an upload size plugin not fix the 413 error?

Those plugins change PHP's upload limit. A 413 comes from the web server or a CDN such as Cloudflare before PHP runs, so the server limit has to be raised, or the file uploaded by SFTP instead.

More fixes

WordPress: "413 Request Entity Too Large"

You upload a theme, a plugin, a video or a big batch of photos and get a plain page saying "413 Request Entity Too Large", or the uploader just says "HTTP error". The file never reached WordPress: the web server in front of it (usually Nginx, sometimes Apache or Cloudflare) has its own size limit and refused the upload. Raising WordPress's or PHP's limit alone does not help while that one stays low. Here is how to tell which limit it is and raise the right one.

What the owner sees

example-bakery.com/wp-admin/update.php?action=upload-theme

What the checks found

Which limit is it? (five minutes)

Read the bottom line of the error page. "nginx" means the Nginx limit (client_max_body_size, 1 MB unless someone changed it). "Apache" points to LimitRequestBody. A Cloudflare-branded page means the upload went over Cloudflare's plan limit (100 MB on Free and Pro).
Check what WordPress thinks the limit is. Go to Media, Add New. It prints "Maximum upload file size". If that says 64 MB and a 5 MB file still gets a 413, the server in front of PHP is the low one, not PHP.
Try a small file. A 200 KB photo that uploads fine while a 3 MB one fails confirms it is a size limit, not a permission or security block (that is a 403 or a 406).
Note when it started. A 413 right after moving host, adding a CDN or switching to a new server panel almost always means the new layer came with the default 1 MB limit.

Fix it, safest first

Upload a different way for today. A theme or plugin zip can go up by SFTP or the host's File Manager into wp-content/themes or wp-content/plugins, then be activated in the dashboard. A big video is better on YouTube or Vimeo and embedded anyway; it keeps the site fast.
Ask the host to raise the web server limit. On shared or managed hosting you usually cannot change Nginx yourself. One line to support does it: "Please raise client_max_body_size (and PHP upload_max_filesize / post_max_size) to 64M for my site." Most hosts do it the same day.
On your own server (Nginx): add client_max_body_size 64M; inside the http or the site's server block, test with nginx -t, then reload Nginx. A panel such as Plesk, CloudPanel or RunCloud has the same setting in its site settings.
On Apache: look for a LimitRequestBody line in the site config or .htaccess and raise or remove it.
Raise PHP's limits to match. upload_max_filesize and post_max_size (a little larger) in the host's PHP settings or php.ini. If the server limit is fixed but PHP is still 2 MB, the upload fails with a different message, covered in the upload error guide.
Over Cloudflare's 100 MB: upload that file by SFTP or through a hostname that is not proxied by Cloudflare. Cloudflare's limit cannot be raised on the Free or Pro plan.
Re-test with the same file and check Media, Add New shows the new maximum.

What you see, what it means, what it needs

What you see	What it means	Usual fix
"413 Request Entity Too Large" with "nginx" at the bottom	Nginx's upload limit, often the 1 MB default	Raise client_max_body_size (host support or server config)
413 page from Apache	LimitRequestBody is set low	Raise or remove it in the site config or .htaccess
Cloudflare-branded 413	Upload over the plan's 100 MB limit	Upload by SFTP or a non-proxied hostname
"HTTP error" in the media uploader on big files only	Often the same 413 hidden behind the uploader	Check the error in the browser's network tab; raise the server limit
"The uploaded file exceeds the upload_max_filesize directive"	PHP's limit, not the web server's	Raise upload_max_filesize and post_max_size
413 started right after a host move or new CDN	New layer came with default limits	Ask the host to match the old limits

What not to do

Do not install an "increase upload size" plugin and expect it to fix a 413. Those plugins change PHP's limit; the web server refuses the file before PHP ever runs.
Do not set the limits to gigabytes "to be safe". A big limit lets anyone push huge requests at the site. 64 MB covers themes, plugins and photos.
Do not keep re-uploading the same file in the hope it goes through. A 413 is a fixed rule, not a hiccup.

Most 413s are one line from the host's support team, or one line in the Nginx config. If you cannot reach the server settings or the error stays after the change, that is what the box below is for. Related: upload errors, incompatible archive, the link you followed has expired.