File Splitter & Merger

Cut any file — video, disk image, database, archive, anything — into numbered parts by size or by part count, and join a part series back into the original file. The split is byte-exact: the merge side concatenates the parts in order, checks that the total size matches, and prints a SHA-256 of the reassembled file so you can compare it against the original. Works with the classic .001/.002 naming, .part01, .split.001 and name[1].ext styles. Everything happens locally in your browser.
Split Merge
Drop one file here, or click to choose it
Up to 200 MB. The file never leaves this machine.
No file selected.
Split by MB per part   |   parts
Naming
Choose a file to see the split plan.
Integrity: the merger concatenates parts strictly by their number, refuses gaps in the sequence, and reports the SHA-256 of the merged result — if you have the original digest (from the Batch File Hash page or a release manifest), comparing the two proves the round trip was byte-exact. Privacy: splitting and merging run entirely in this tab.

What is file splitting?

Splitting means cutting one file into several smaller files at byte boundaries: part 1 holds bytes 0 to N-1, part 2 holds bytes N to 2N-1, and so on. No compression, no container, no transformation — the concatenation of all parts, in order, is exactly the original file. That is why the same operation reverses itself: merging is nothing more than pasting the parts back together in the right order.

People split files to fit size limits — an email attachment cap, a FAT32 USB stick's 4 GB ceiling, an upload form — or because a download that can resume per-part is friendlier on a bad connection than one huge transfer.

The naming conventions

StyleExampleTypical producer
name.001backup.zip.001split, HJSplit, 7-Zip (“split to volumes”)
name.partNNmovie.mkv.part01WinRAR when not compressing
name.split.NNNdata.bin.split.001custom scripts, some FTP re-upload tools
name[N].extimage[1].pngscanner/camera batch exporters

The merger recognises all four, groups the files by their shared base name, sorts them by the number, and refuses to proceed if the numbering has a hole (a missing part would silently corrupt the result — better to stop).

What splitting is not

It is not compression — the parts together are the same size as the input (plus a few bytes of ZIP wrapper if you take the ZIP download). It is not encryption — each part is plain content; use the AES tool first if you need secrecy. It is not a video editor — cutting a video into byte-parts does not make each part independently playable; that requires re-muxing, which is a different job.

FAQ

Why is there a 200 MB / 1 GB limit? — the whole file lives in the browser's memory during the operation; beyond that the tab can exhaust RAM.
Can I merge parts someone else split with another tool? — yes, if they used plain byte-splitting with one of the naming conventions above. Archives that were compressed while splitting (multi-volume RAR/7z) are a different format and need their own tool.
Is the ZIP download lossless? — yes; the ZIP stores each part as-is (store method, no re-compression), so extracting it gives you the exact parts.
Do you keep my files? — no; close the tab and everything is gone.

Self-test