How it works

Break a large file into fixed-size chunks for email attachments, network upload limits, or storage constraints.

Drop any file. Pick a chunk size: 1, 5, 10, 25, 50, or 100 MB. The tool slices the file into byte-aligned parts and bundles them into a ZIP, with each part named yourfile.part001.ext, yourfile.part002.ext, etc., zero-padded so they sort correctly. A README.txt inside the ZIP includes the exact commands to reassemble (cat on macOS / Linux, copy /b on Windows). The parts are byte-identical to slices of the source, so reassembly produces a bit-exact copy. Useful when an upload limit (Gmail 25 MB, some chat apps 100 MB) is too small for your file. The parts can be re-emailed, re-uploaded, or stored separately and stitched back together. Output filename has -split.zip appended.

How to use it

1. Drop your file. Any file type — the split is a raw byte slice, so reassembly is bit-exact.
2. Pick a chunk size. Choose 1 to 100 MB; pick the largest size your email or upload limit allows.
3. Split. The parts are bundled into a ZIP with a README containing the exact cat / copy commands.
4. Reassemble later. Run the command from the README to stitch the parts back into a bit-exact copy.

Frequently asked questions

How do I reassemble the split files?

On macOS / Linux: cat yourfile.part*.ext > yourfile.ext. On Windows: copy /b yourfile.part001.ext+yourfile.part002.ext... yourfile.ext. The exact commands are in the README inside the ZIP.

Will the reassembled file be exactly the same?

Yes, bit-for-bit. The parts are raw byte slices, concatenation produces a bit-exact copy.

What size chunks should I pick?

Pick the largest size your transport allows. For Gmail attachments, 20 MB or smaller (Gmail's limit is 25 MB after encoding overhead). For Discord, 25 MB. For private FTP, 100 MB.

Is my file uploaded?

No. The split happens locally; the chunks are bundled into a ZIP via JSZip in your browser.