PHP中Upload_Max_Filesize是否有上限？能否设置为50G？

Hey Greg, I get why your question got mislabeled as duplicate—you're focused on hard upper limits of the directive, not how to configure it, so let's clarify this properly:

• Does upload_max_filesize have a built-in maximum in PHP?
  Nope, PHP itself doesn’t enforce a hard-coded upper limit for this setting. The only constraints come from your server’s environment and available resources, not the PHP core itself.

• Can you set it to 50GB on a self-hosted server you control?
  Technically, yes—you absolutely can define upload_max_filesize = 50G in your php.ini (or per-directory config like .user.ini). But there are critical related settings you’ll need to adjust too, otherwise the large upload will fail:

  • post_max_size must be larger than upload_max_filesize (since POST requests include more than just the file data) — e.g., set it to 51G
  • memory_limit needs to be sufficient (PHP streams uploads by default now, so this is less critical than it used to be, but don’t set it absurdly low)
  • Your web server has its own limits:
    • For Apache: Adjust LimitRequestBody (set it to a value larger than 50GB, or 0 for unlimited)
    • For Nginx: Update client_max_body_size to match or exceed your upload_max_filesize
  • You’ll also need to bump up max_execution_time and max_input_time to give the upload enough time to complete (50GB will take ages over any standard connection!)

  That said, practicality-wise, uploading 50GB files via PHP isn’t the most common approach—most folks use chunked uploads or dedicated file transfer tools for such large files. But from a configuration standpoint, it’s totally doable if you tweak all the related settings.

内容的提问来源于stack exchange，提问作者Greg