How I Built a Single-File PHP File Manager That Bypasses upload_max_filesize

Description and use

A single‑file PHP file manager that bypasses upload_max_filesize by chunking uploads into 2 MB pieces and reassembling them server‑side.

Problem

Standard file uploaders fail on cheap cPanel hosts because upload_max_filesize is capped at 2 MB, max_execution_time is 30 s, memory_limit is too low, and security modules block requests containing cmd=, exec=, eval=, or ../.

Outcome

The file manager successfully uploads files larger than 2 MB on shared hosting by chunking uploads and reassembling them server‑side, overcoming PHP limits and security module restrictions.

Workflow

• 1. Browser slices the file into 2 MB chunks.
• 2. Each chunk is uploaded via AJAX to the server.
• 3. Server receives a chunk and appends it to the target file using stream pipes.
• 4. The process repeats until the entire file is assembled.

Evidence

upload_max_filesize is capped at 2MB

Source

Standard file uploaders try to POST the whole file. That fails.

Source

The browser slices files into 2MB chunks and uploads them one at a time via AJAX.

Source

Server-side reassembly uses stream pipes: php $out = fopen($target, 'ab'); $in = fopen($chunkPath, 'rb'); while (!feof($in)) { fwrite($out, fread($in, 65536)); } fclose($in); fclose($out);

Source