413 Request Entity Too Large

Common causes

• nginx's client_max_body_size is at its default of 1 MB.
• An application or framework body-size limit (e.g. a JSON parser limit).
• A CDN or platform upload limit (Cloudflare Free and Pro accept up to 100 MB).

How to fix it

1. Raise the nginx limit in the http, server or location block: client_max_body_size 50m; then reload.
2. Raise the matching limit in the app (e.g. LimitRequestBody in Apache, the body parser limit in Express).
3. For very large files, upload directly to object storage with presigned URLs or in chunks.