File Merger
Combine text/CSV.
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Rejoining split files
Merging concatenates the parts of a split file back into one, in order, byte for byte. If every part is present and the sequence is correct, the result is bit-identical to the original — the same file, not an approximation.
Everything therefore depends on order and completeness. Parts sorted alphabetically rather than numerically will misorder anything past part nine, since part10 sorts before part2 in a plain text sort. A missing part produces a file that is subtly broken rather than obviously so: an archive that will not extract, a video that plays and then stops. Comparing a checksum of the merged output against the original is the only way to be certain, and it is worth doing before you delete anything.
Why we built this tool
You merge when a large file arrived in pieces — a backup emailed in parts, an archive downloaded as segments, or a file someone split to get it past an attachment limit.
These are typically backups and archives containing everything a person or a business keeps. Uploading all the parts to a merging service means reassembling your complete dataset on someone else's machine. Ours concatenates in your browser using the File API, so nothing is transmitted, there is no total size limit beyond your device's capacity, and no account is required to handle a file of any size.
Tips and common mistakes
- Order parts numerically, not alphabetically — part10 sorts before part2 in a plain text sort.
- Confirm the sequence is complete; a gap produces a subtly broken file rather than an obvious error.
- Compare the merged size against the sum of the parts as a first check.
- Open or checksum the result before deleting the individual pieces.
Quick start: using File Merger
- Add all the parts of the split file.
- Check they are in numeric order, not alphabetical order.
- Confirm no part is missing — the sequence must be complete.
- Run the merge and download the reassembled file.
- Open it, or compare its checksum with the original, before deleting the parts.
The matching operation is File Splitter; check what you ended up with using File Inspector.