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File Splitter

Split large files into smaller parts

Supports files up to 5 GB and up to 1,000 parts. Splitting is instant — chunks are lazy byte-range views, not copied into memory.

Click or drop a file here

About File Splitter

File Splitter is a free online tool that divides any file into smaller, numbered parts by size — entirely in your browser, with nothing uploaded to a server. It's useful for staying under email attachment limits, upload size caps, or storage constraints.

How to use File Splitter

  1. 1Click the upload area and select the file you want to split.
  2. 2Set your chunk size and unit (Bytes, KB, or MB).
  3. 3Click "Split File" to divide it into numbered parts locally.
  4. 4Download each part individually — you'll need all of them together to reconstruct the original file.

Frequently Asked Questions

What file types can I split?

Any file type — splitting works purely on raw bytes, so there are no format restrictions.

Does File Splitter include a way to merge the parts back together?

Not on this page — this tool only splits files. You'll need a separate file-joining utility, or a command like "copy /b" on Windows or "cat" on Mac/Linux, to reassemble the parts in order.

Is there a file size limit?

Files up to 5 GB are supported, and a split can't produce more than 1,000 parts (pick a larger chunk size if you hit that). Splitting itself doesn't load your file into memory -- each part is a lazy byte-range view of the original, only read when you actually download it -- so file size isn't the limiting factor the way it is for tools that have to process a file's full contents.

Is my data private?

Yes. Splitting happens entirely in your browser — your file is never uploaded to a server.

Tips & Tricks

  • ✓Parts are numbered sequentially and automatically — keep them together in the same folder and in order for easy reassembly.
  • ✓Pick a chunk size just under your target limit (e.g. 24MB for a 25MB email attachment) to leave room for any encoding overhead.
  • ✓Splitting is instant regardless of file size, since parts are lazy views rather than copies — only downloading a part actually reads its bytes.
  • ✓Keep the original file until you've confirmed you can successfully rejoin and use the split parts.