File Splitter
Split a large file into numbered chunks that fit size-limited forms, emails or volumes.
What is File Splitter?
A splitter for files that are too big for a channel: an upload form capped at 100 MB, an email attachment limit, or a FAT32 volume. It produces numbered parts that the File Joiner can rebuild.
How it works
The file is read into memory and cut at exact byte boundaries. Each part is named with a zero-padded numeric suffix — backup.zip.001, .002 — so the correct order is unambiguous and a missing chunk is immediately visible. Parts can be downloaded one by one or bundled into a single .zip.
- Add your files. Drop files (or a whole folder) onto the drop zone. Browsers hand the contents straight to the page, so nothing is uploaded.
- Choose the options. Pick the format, compression, naming rule or split size. Any change re-computes the preview immediately.
- Download the result. Run the tool and grab the archive, the extracted files or the report. Multi-file results come back as a single .zip.
Examples
Splitting a 3.2 GB disk image for a 500 MB upload form
Seven 500 MB parts, each small enough for the form, reassembled later with the File Joiner.
Emails capped at 25 MB
Split a 90 MB PDF scan into four 25 MB parts and send them across messages; the numbered suffixes keep the order obvious for the recipient.
Common mistakes
Expecting ZIP to shrink photos, video or audio
Those formats are already compressed; deflate typically saves single digits on them. ZIP is at its best on text, JSON, CSV, logs and source code.
Treating ZipCrypto as real encryption
Traditional ZIP encryption is legacy and breakable. It stops casual snooping only — for secrets, encrypt the contents with AES-256 first.
Renaming extensions to convert a file
Changing .png to .jpg does not change the bytes inside. Some programs will refuse the file, or display garbage. Use a real converter when the format must change.
Splitting without keeping the suffixes
The parts carry .001, .002 … suffixes on purpose: the joiner orders them by number and fails loudly when one is missing, instead of producing a corrupt file.
Frequently asked questions
How do I put the parts back together?
Use the File Joiner on this site, or concatenate them in order on any system: cat backup.zip.001 backup.zip.002 > backup.zip. The numeric suffixes make the order explicit, and the joiner refuses a set with a gap.
Does splitting compress anything?
No — parts are exact slices of the original bytes, so joining them restores the file bit-for-bit. Compress first if you also want the transfer to be smaller.
Why is the .zip of parts such a small file?
The parts are stored without compression, so the .zip is essentially the sum of the parts plus a small index. It exists to give you a single download, not to shrink anything.