File Joiner
Rejoin split file parts back into the original file
100% free. Runs entirely in your browser - your files and data never leave your device and nothing is uploaded to any server.
Drop all parts here or click to select them
Files ending in .part1, .part2, …
About this tool
Rejoins file parts that were previously split (using the File Splitter or a similar tool) back into the original, complete file - the necessary second step after transferring split pieces through a size-limited channel.
How to use this tool
- Collect all split partsEnsure every chunk from the original split set is available.
- Load parts into joinerImport complete set so tool can reconstruct in sequence.
- Rebuild original fileMerge binary chunks into full file output.
- Validate reconstructed fileOpen or checksum-verify to confirm exact restoration.
Rebuilding a split file correctly
Add every part and make sure they are in order - part 1, part 2, part 3 - before joining. The rebuilt file is byte-for-byte identical to the original when all the parts are present and in the right order.
To be certain, compare the checksum of the rebuilt file with one taken from the original, using the File Checksum Generator.
Key features
- Restores original file exactly when all parts are present.
- Completes split-transfer workflow safely.
- Avoids command-line complexity for file reassembly.
- Useful for non-technical users receiving chunked files.
Common uses
- Reassembling email-transferred split archives.
- Reconstructing large media moved via small USB chunks.
- Recovering distributed backup pieces into original file.
- Validating integrity after segmented transfer process.
Tips for better results
- Keep original part filenames and sequence unchanged.
- Verify all parts have completed downloads before joining.
- Compare resulting file size against source expectation.
- Use checksums for high-value or sensitive outputs.
Mistakes to avoid
- Attempting join with one missing/corrupted part.
- Loading parts from different split sessions together.
- Ignoring part order mismatch warnings.
- Assuming partial join output is usable.
Frequently asked questions
The tool typically identifies the correct order from the parts' naming/sequencing, but make sure you have ALL the parts from the original split - missing even one part will result in a corrupted or incomplete rejoined file.
Yes - if all parts are present and correctly rejoined, the reconstructed file is byte-for-byte identical to the original file before it was split.
The rejoined file will be incomplete or corrupted - all parts from the original split are required to reconstruct the file correctly.
Compare its size with the original, or better, compare a SHA-256 hash of both. If the hashes match, the file is byte-for-byte identical.
Joining depends on order, so sort the parts by their number suffix (.001, .002 ...) before selecting them. A part in the wrong place produces a file that will not open.
Yes, if they are plain byte splits, which is what those tools produce with numbered .001, .002 files. Archives split as multi-volume ZIP or RAR need their own extractor instead.