# Split a Large File into Parts

When an email or a website only accepts 20 or 25 MB, cut the file into numbered parts that fit, send them separately, and let the recipient join them back into the identical original.

_Source: https://sharelargefilesfree.com/tools/split-file · Updated 2026-09-29_

## How to use it

1. Choose or drop the file: any type, up to 2 GB.
2. Pick a part size (for example 24 MB for Gmail) or a number of parts.
3. Keep the checksum file switched on.
4. Press Split file, then save or send the parts and the .parts.json file.

## The honest part: the recipient must join them

A part such as `video.mp4.002` is just a slice of bytes; it does not open on its own. Whoever receives the parts needs all of them and must join them in order, with [Join files](https://sharelargefilesfree.com/tools/join-files) (free, in the browser, on any device), with 7-Zip, or with one command: `copy /b video.mp4.001+video.mp4.002 video.mp4` on Windows, `cat video.mp4.0* > video.mp4` on Mac and Linux. Tell them before you send.

Often there is a simpler way: [send the whole file with one link](https://sharelargefilesfree.com/), free up to 20 GB, and nothing needs joining. Splitting is for when a link is not allowed, such as an upload form or a system that only takes attachments.

## Checked to the last byte

With the checksum file on, the tool calculates the SHA-256 fingerprint of the whole file and of every part and writes them to a small `.parts.json` file. Join files reads it, puts the parts in the right order, spots a missing or damaged part by name, and confirms that the joined file is byte-for-byte identical to your original.

## Part sizes for common limits

| Limit | Part size to choose |
| --- | --- |
| Gmail, Yahoo attachments (25 MB) | 24 MB |
| Outlook.com, many company mail servers (20 MB) | 19 MB |
| Discord free, some forms (10 MB) | 9 MB |
| Upload forms with a 100 MB cap | 95 MB |

Email adds about a third to attachments in transit (encoding), which is why the email sizes leave room under the limit. Parts are cut in your browser without loading the whole file into memory, so even large files split in a moment.

## Frequently asked questions

### How do I split a large file to email it?

Choose the file, pick 24 MB (Gmail) or 19 MB (Outlook), press Split file and attach one or two parts per email, plus the small .parts.json file.

### How does the recipient put it back together?

They open Join files, add all the parts and the .parts.json file and press Join; the result is checked against the original. 7-Zip or copy /b / cat work too.

### Can I split a video or ZIP file?

Yes, any file type. Parts are byte ranges, so the type does not matter.

### Are the parts compressed?

No. To make a file smaller first, use Compress video or Zip files.

### Is my file uploaded?

No. It is split on your device.