Why your file won't fit in email, and what to do instead
Most email services cap attachments at 20 to 25 megabytes — Gmail tops out at 25 MB, Outlook at 20 MB. If your file is larger, the email simply bounces back with an error message. You have three working options: compress the file to make it smaller, split it into pieces, or use a file-sharing service that the recipient can download from instead of receiving as an attachment.
The fastest route depends on what kind of file you're sending and whether the recipient needs it right away. A video file or folder full of photos almost always needs a sharing service. A single document or spreadsheet might compress enough to fit through email. A collection of smaller files can sometimes be split and sent in separate emails.
Key Takeaways
- Email attachments have size limits — usually 20 to 25 megabytes — and files larger than that will bounce back undelivered.
- Compressing a file with your operating system's built-in tools can shrink it by 50 percent or more, though video and photo files compress poorly.
- File-sharing services like Google Drive, Dropbox, or WeTransfer let you upload once and share a download link instead of sending the file through email.
- Splitting a large file into smaller pieces and sending them in separate emails works but requires the recipient to reassemble them afterward.
- Video files, image collections, and folders almost always need a sharing service because compression does not reduce their size enough.
Compressing a file to fit through email
Compression works best on documents, spreadsheets, and text files — anything that contains repeated information. Right-click the file, look for an option called "Compress", "Zip", or "Send Compressed", and your operating system will create a smaller version. On Windows, this is built in. On Mac, right-click and choose "Compress". The compressed file usually shrinks to 30 to 50 percent of its original size.
Video and photo files compress poorly because they are already compressed when you take them. Trying to compress a video file again might shrink it by 5 to 10 percent at most, which usually is not enough to get under the email limit. If you have a folder full of photos or a video file, skip compression and use a file-sharing service instead.
After you compress the file, check its new size by right-clicking and selecting "Properties" (Windows) or "Get Info" (Mac). If it is still over 20 MB, compression alone will not work — move to file-sharing instead.
Using Google Drive, Dropbox, or OneDrive to share large files
File-sharing services let you upload a file once and send a link instead of the file itself. The recipient clicks the link and downloads it from the service. This works for files of any size and is the most reliable method for video, photos, or folders.
Google Drive is free with a Google account and gives you 15 GB of storage. Upload your file, right-click it, select "Share", and copy the link. Paste that link into an email. The recipient does not need a Google account to download — they can open the link in any browser.
Dropbox offers 2 GB free and works the same way. Upload, share the link, send it in email. OneDrive (Microsoft's service) gives 5 GB free and integrates with Outlook, so you can share directly from the attachment button without leaving email.
If you do not want to create an account, WeTransfer lets you send files up to 2 GB without signing up. Upload your file, enter the recipient's email address, and WeTransfer sends them a download link automatically. You do not need to write an email yourself.
Splitting a large file into smaller pieces
If you cannot use a file-sharing service and compression did not work, you can split the file into smaller chunks and send them in separate emails. This requires the recipient to reassemble them afterward, so it is slower and more error-prone than other methods. Only use this if the recipient specifically asks for it or if you have no other option.
On Windows, use 7-Zip (free, download from 7-zip.org). Right-click the file, choose "7-Zip", then "Add to Archive". In the dialog box, find the field labeled "Split to volumes, bytes" and enter 15000000 (15 MB). This creates multiple files you can email separately. The recipient needs 7-Zip installed to reassemble them.
On Mac, the built-in Archive Utility does not split files. Download Keka (free from keka.io) or use the command line. Most Mac users find it easier to use a file-sharing service instead.
When to use each method
| File type | Best method | Why |
| Document, spreadsheet, or text file under 50 MB | Compress and email | Compression shrinks these files significantly, and email is fastest. |
| Video file or photo collection | File-sharing service | Compression does not reduce size enough; sharing avoids email limits entirely. |
| Folder with mixed files | File-sharing service | Easier than compressing and splitting; recipient gets everything in one download. |
| File over 100 MB with no account available | WeTransfer | No signup required; handles large files and sends the link automatically. |
| Recipient specifically requests split files | Split and email | Only use if asked; requires recipient to reassemble. |
Troubleshooting when the file still will not send
If you compressed the file and it still bounces back, the email service rejected it for a different reason. Some email providers block certain file types for security — executable files (.exe), scripts, or files that contain macros. Check the error message; it usually tells you why.
If the error says "attachment too large" even after compression, the file is still over the limit. Move to a file-sharing service. If the error mentions the file type, ask the recipient if they can open it in a different format. A Word document can often be saved as a PDF, which compresses better.
If you are using a work email account, your company may have set a lower attachment limit than the public email service. Ask your IT department what the limit is and whether they have a preferred file-sharing tool. Many companies use SharePoint, Box, or their own internal system.
Frequently Asked Questions
Can I compress a file multiple times to make it smaller?
No. Compressing an already-compressed file does not reduce its size further. If you compress a file and it is still too large, the file type itself does not compress well — video, audio, and photos fall into this category. Switch to a file-sharing service instead.
Will the recipient be able to open a compressed file?
Yes. Windows, Mac, and Linux all have built-in tools to open .zip files without installing anything. The recipient just double-clicks the compressed file and it opens automatically. No special software is needed.
Is it safe to use WeTransfer or Google Drive with sensitive files?
These services use encryption in transit, so files are protected while traveling over the internet. However, once uploaded, the file sits on their servers. If you are sending financial records, medical information, or other highly sensitive data, check your organization's policies first. Some workplaces require you to use their own secure file-sharing system instead.
What happens if the recipient does not download the file within a certain time?
Google Drive and Dropbox keep files indefinitely as long as they are in your account. WeTransfer deletes files after 7 days if they are not downloaded. If you are using WeTransfer and the recipient misses the window, you can upload and share the file again.
Can I send a compressed file through a file-sharing service?
Yes. If you want to compress first to reduce upload time, compress the file, then upload the compressed version to Google Drive or Dropbox. The recipient downloads the compressed file and decompresses it on their end. This is useful if your internet connection is slow, but it adds an extra step for the recipient.