File Splitter

About File Splitter

This tool splits large files into smaller chunks. Upload your file, choose a split method (by size, by number of parts, or PDF page range to extract specific pages into a standalone PDF), and download the chunks. Each part — and the original file — gets a SHA-256 checksum, plus a downloadable sha256sum-compatible CHECKSUMS.txt so you can prove every part transferred intact and the rejoined file is bit-identical. Useful for email attachments, cloud storage limits, or transferring large files. All processing happens in your browser for complete privacy.

How does the file splitter work?

Upload a file, choose how to split it (by chunk size or number of parts), and click Split File. The tool divides your file into smaller chunks and lists each part below, so you can download them individually or all at once as a ZIP. You can then transfer or store these parts separately.

What's the difference between split methods?

Split by Size: You specify the size of each chunk (e.g., 10MB), and the tool creates as many parts as needed. Split by Parts: You specify how many parts you want, and the tool divides the file evenly into that many chunks.

How do I rejoin the split files?

To rejoin split files, you need to concatenate them in order. On Windows, use: copy /b file.part001 + file.part002 + file.part003 output.file. On Linux/Mac: cat file.part* > output.file. Future updates may include a File Joiner tool.

What are the size limits?

There's no strict file size limit, but splitting very large files (over 2GB) may be slow depending on your browser and device. The maximum number of parts is 1000 to prevent excessive splitting.

Why split files?

File splitting is useful for: bypassing file size limits (email attachments, cloud storage), transferring large files over unstable connections, storing files on multiple drives, or creating backups across different media.

Are the file names important?

Yes! The split parts are named sequentially (file.part001, file.part002, etc.). Keep the original filenames and order to successfully rejoin them later.

Is my file safe?

Absolutely! All file splitting happens directly in your browser. Your file is never uploaded to any server. Everything stays private on your device.

Can I split any file type?

Yes! This tool works with any file type - documents, images, videos, archives, executables, databases, and more. The file is split at the binary level, so the type doesn't matter.

How do I verify the split or rejoined file is intact?

Every split generates SHA-256 checksums for each part and the original file, shown in the results table and saved to a sha256sum-compatible CHECKSUMS.txt (also bundled inside the ZIP). After transferring the parts, run 'sha256sum -c CHECKSUMS.txt' on Linux/Mac to confirm each part arrived intact. On Windows, use 'Get-FileHash part001 -Algorithm SHA256' and compare. To prove the rejoined file is bit-identical, hash it the same way and match it against the original SHA-256 listed in the manifest header.

What chunk size should I use for email or cloud limits?

Match the chunk size to the receiving channel's cap, leaving a small margin for encoding overhead. Gmail attachments max out at 25MB and Outlook at 20MB, so use ~20MB and ~18MB parts respectively. Discord allows 25MB on free tiers, WeTransfer free is 2GB per transfer. For older USB/FAT32 media keep parts under 4GB. Split by size, set the unit to MB, then verify with the CHECKSUMS.txt after upload.