How to create a ZIP file that is small enough to email
Learn how to compress several files into ZIP parts small enough to email, including a simple way to make Gmail-sized archives.
Create one ZIP archive from your files, then split it into smaller ZIP parts sized for your email provider’s attachment limit. Send every part in separate messages or alongside one another, and tell the recipient to download all parts before extracting the archive. This is more reliable than trying to attach one oversized folder.
1. Gather only the final files. Remove duplicates, drafts, and files the recipient does not need. Fewer files mean a smaller archive and fewer email attachments to track.
2. Reduce large files before zipping. ZIP compression helps most with documents and other uncompressed files. Photos, videos, and previously compressed downloads may shrink very little, so resize images or compress PDFs first when possible.
3. Leave room below the attachment limit. Email services can add overhead to attachments. Instead of making each part exactly the maximum permitted size, choose a slightly smaller part size (for example 20 MB for Gmail) to reduce the chance of a rejected message.
Decide whether to split the archive
- Everything fits in one email → Make one ZIP file. Simplest for the recipient, but may not reduce already-compressed media much.
- The archive is too large to attach → Split the ZIP into email-sized parts with Files to ZIP. The recipient must download every part before extracting.
- One or two files cause the problem → Reduce or replace those files first (for PDFs, use Compress PDF). May affect image, video, or document quality.
Steps to make email-sized ZIP parts
1. Put the files you want to send in one folder and check that they open correctly.
2. Open Files to ZIP on CompanionPDF.
3. Add the files and choose a part size safely below your email attachment limit (20 MB for Gmail works well).
4. Create the archive, keeping every generated part together. Do not rename or delete individual parts.
5. Attach the parts to email messages. Label the messages clearly, such as “Part 1 of 3,” “Part 2 of 3,” and “Part 3 of 3.”
6. Ask the recipient to save all parts in the same folder, then extract the first part with software that supports split ZIP archives.
Splitting solves an attachment-size problem, not a compression problem. If the files remain large after zipping, you will have more parts to send. For sensitive material, remember that a ZIP file is still an email attachment; use the sharing method required by your organization.
Where CompanionPDF fits
CompanionPDF’s Files to ZIP tool compresses several files into a ZIP and can split them into Gmail-sized ZIP parts. It is free to use, requires no account or payment, and files are deleted right after download. For a single heavy PDF, start with Compress PDF; for sending tips, see how to send a PDF by email without errors.
FAQ
Can I send the ZIP parts in separate emails?
Yes. Number each message and make sure the recipient receives every part. They need to download all parts into the same folder before extraction.
Why did my ZIP file barely get smaller?
Many image, video, and downloaded archive formats are already compressed. A ZIP can still organize them into one archive, but it may not reduce their size much.
Does the recipient open every ZIP part separately?
No. They should keep all parts together and start extraction from the first part using a tool that supports split ZIP archives. Opening only a later part will not reconstruct the full set of files.