File Joiner
Reassemble numbered file chunks back into the original file, in the correct order.
What is File Joiner?
The counterpart to the File Splitter: it takes a set of numbered chunks and rebuilds the file they came from.
How it works
Parts are ordered by their numeric suffix rather than by the order you picked them, and the sequence is validated — a missing or duplicated number is reported instead of producing a corrupt file. An optional expected size acts as a second check before joining.
- 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
A 240 MB photo folder → a 52 MB .zip
JPEGs are already compressed, so the archive only saves 10–15% — but adding the folder structure and a manifest makes the upload verifiable.
A download cut off at 1.4 GB
The File Splitter cuts it into 500 MB chunks that fit the host's limit, and the File Joiner reassembles them, refusing any set with a missing part.
A release bundle with checksums
The Manifest Generator writes sha256sum-style lines next to the files, so the recipient can prove the download arrived intact.
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
What if a chunk is missing?
The join is refused with the list of numbers found, so you know exactly which part to re-download. You can also set the expected total size for an extra check — a mismatch means something is truncated.
Does it work with parts made by other tools?
Yes, as long as they end in .001, .002, … — split, 7-Zip volumes and most Unix split conventions all match. Files whose suffixes are not numeric are reported so you can rename them.
How big a file can it rebuild?
As large as the tab's memory allows, since the join happens in memory before the download is created. Multi-gigabyte sets are better joined with cat or tar on the command line.