Join split files
The pieces back into the file they came from.
Drop files here
or click to choose from your device
Up to 3 files per runUp to 150 MB per file5 runs per dayRemove limits with Pro✓ Works offline
Your files stay on your device
This tool runs entirely in your browser. Nothing is uploaded, nothing is stored, and you can even turn off your internet connection before you start.
Example
Example: a 23.4 MB PDF that was split into three parts for email
Someone sent tax-return-2025.pdf in three emails because their mail takes only 10 MB: tax-return-2025.pdf.001 and .002 at 10.0 MB each, and .003 at 3.4 MB. Save all three and drop them here, in any order.
- The parts are put in order by the number at the end of the name — .001, .002, .003 — whatever order they were added in.
- The numbers are checked for gaps: with .002 left out, the join stops with “Part 2 is missing. All the parts have to be here, or the file comes back damaged.”
- Press Join: the bytes are put back end to end, with nothing added and nothing compressed.
| Pieces named | Joined file |
|---|---|
| tax-return-2025.pdf.001, .002, .003 | tax-return-2025.pdf |
| movie.mkv.1, movie.mkv.2 | movie.mkv |
| backup.zip.aa, backup.zip.ab | backup.zip |
tax-return-2025.pdf, 23.4 MB, the same byte for byte as before it was split; the page notes “3 parts, 23.4 MB in all.” Open it as usual.
How it works
- Add every piece — .001, .002, .003 and so on. The order you add them in does not matter.
- Check that none is missing. A gap in the numbers is refused, but a missing last piece cannot be seen: count the pieces against what was sent.
- Press join. You get the original file back, byte for byte.
- Open it to be sure. A joined archive or video that opens is a joined file that is right.
Frequently asked questions
- What if one piece is missing?
- If a number in the middle is missing — .001 and .003 without .002 — the join is refused and you are told which number is absent. A missing last piece cannot be seen, because nothing in the pieces says how many there were: count them against what was sent, and open the joined file to be sure. If every piece is exactly the same size, as all but the last piece of a split are, the note shown with the result warns that a last piece may be missing.
- Which naming does it understand?
- A number at the end of the name: .001, .002, and also .1, .2, or counting from 0. Letters as the split command writes them work too: xaa, xab, or backup.zip.aa, backup.zip.ab. That covers what our splitter, 7-Zip and the Unix split command produce.
- Can it join .part1.rar or .z01 files?
- No. Those are archive formats with their own headers in each piece, not plain slices of bytes — open them with 7-Zip or WinRAR, which understands them.
- How do I open .001 and .002 files?
- They are not files of their own but pieces of one file. Add all of them here and press Join to get the original back — a video, a PDF, a ZIP — and open that as usual. If it is a ZIP or 7z archive, extract it afterwards.
- What is the joined file called?
- The pieces’ name without the number: tax-return-2025.pdf.001 joins to tax-return-2025.pdf, backup.zip.aa to backup.zip. Pieces with no name of their own, like xaa and xab, give a file called x-joined.
- Is anything uploaded?
- No. The pieces are read and written back out in your browser.
Related tools
⋈ Split a file Numbered pieces small enough to send. ☷ Extract a ZIP Open an archive and take out the files, on a device that has no unzip program. ☷ Create a ZIP Bundle files into one archive. Nothing is uploaded, so nothing has to be trusted. ⧉ PDF tools Merge PDF Combine PDFs into one document, in the order you choose, without sending them anywhere.