Manatee

Gmail's 25 MB attachment limit: how to get a file under it

· 6 min read

Gmail allows up to 25 MB of attachments per message; anything larger is automatically turned into a Google Drive link instead. If you would rather send the actual file, the fix depends on what it is: a video needs re-encoding at a lower bitrate or resolution, a PDF needs its images downsampled, and a batch of photos needs resizing. On a Mac, QuickTime and Preview handle the rough version of each, and a shrink tool that targets a size in MB handles the exact version.

What the 25 MB limit actually covers

The 25 MB figure is the total for all attachments on one message, not per file. Three 10 MB PDFs on one email exceed it. When you attach something over the limit, Gmail does not refuse; it uploads the file to Google Drive and inserts a link, and the recipient needs to click through (and, depending on your sharing settings, may need to sign in).

Two details that catch people:

  • Other providers have lower limits. If you are sending to an Outlook, corporate Exchange or older ISP address, the receiving side may cap messages at 10 or 20 MB regardless of what Gmail allows. The message leaves fine and bounces later. A comfortable target for any recipient is under 20 MB of attachments. The figures by provider are in email attachment size limits by provider.
  • Attachments grow in transit. Email encodes attachments as text, which inflates them by about a third. Gmail’s limit is applied to the file sizes you see, but a strict receiving server that measures the whole message will see a 20 MB attachment as roughly 27 MB. Again, margin helps.

Gmail can receive messages up to 50 MB, so a file coming the other way from a generous provider is fine.

Step 1: know what kind of file you are dealing with

Select the file in Finder and press Command-I. Size is at the top; the Kind line tells you what you have. The fix is different for each:

  • Video (.mov, .mp4, .m4v): the most common offender. A one-minute iPhone 4K clip is well over the limit on its own.
  • PDF: large when it contains scans or full-resolution photos.
  • Photos (.heic, .jpg): a modern phone photo is 2 to 5 MB each; ten of them break the limit.
  • Office documents: large when they embed images or video, or when a PowerPoint has high-resolution pictures on every slide.
  • Zip archives: already compressed; squeezing them again does nothing.

Get a video under 25 MB

Twenty-five megabytes is not much video. At a bitrate that looks good for 1080p, it is around one to two minutes. For a longer clip, you will be choosing between resolution, length and a link.

The quick route, with no installation:

  1. Open the clip in QuickTime Player.
  2. Trim anything you do not need with Edit > Trim.
  3. Choose File > Export As and pick 720p (or 480p for a long clip).
  4. Save under a new name and check the size in Finder.

QuickTime gives you a preset and a result; if the result is 31 MB, your only lever is a lower resolution. When the number matters, Manatee is the more direct tool: switch to Shrink, drop the video in, type 20 as the target in MB (leaving margin for the encoding overhead above), and it finds the quality that fits and writes a new copy beside the original. The original is never modified and nothing is uploaded; the encoding runs on your Mac. Every feature is free for the first 24 hours.

Manatee cannot trim or cut a video, so do that in QuickTime first. And it cannot make a ten-minute 1080p clip look good at 20 MB; no encoder can. For anything past a few minutes, send a link (below) or split the clip. There is a fuller walkthrough in how to compress a video to email it from a Mac.

Get photos and PDFs under the limit

Photos. Apple Mail resizes for you: after attaching images, a pop-up menu labeled Image Size appears at the right of the header area; pick Medium, which is typically 200 to 400 KB per photo and looks fine on any screen. Gmail in the browser has no such option, so resize first. In Preview, open the photos, select all in the sidebar, choose Tools > Adjust Size, set the width to 1600 pixels, and export. HEIC photos from an iPhone may also need converting for recipients who cannot open them.

PDFs. Open the file in Preview, choose File > Export, and pick Reduce File Size from the Quartz Filter menu. If the result looks too rough, the options for a gentler filter and for shrinking to an exact size are in how to compress a PDF on a Mac.

Word and PowerPoint files. In Word or PowerPoint for Mac, select a picture, open the Picture Format tab, and use Compress Pictures with “All pictures in this file” and a web or email resolution. Save a copy.

Zipping: when it helps and when it does not

Right-click a file in Finder and choose Compress to make a zip archive. For documents, spreadsheets and text, this can cut the size by half or more. For video, photos, PDFs and anything already compressed, it does almost nothing; a 40 MB MP4 becomes a 39.8 MB zip. The attachments Gmail is most likely to reject are exactly the ones zipping cannot help.

Zipping is still useful for bundling: ten resized photos into one attachment is tidier than ten files, and a zip of a 15 MB folder of Word documents will usually slip under a 10 MB corporate limit.

When a link is the better answer

Sometimes the correct move is to stop fighting the limit. If the file is a long video, a set of original-quality photos for printing, or anything the recipient needs untouched, send a link:

  • Google Drive: Gmail does this automatically over 25 MB. Check the sharing setting it applies so the recipient does not hit a permission wall.
  • Mail Drop: in Apple Mail, large attachments are offered via iCloud Mail Drop. The recipient gets a download link that expires after 30 days, and the file does not count against your iCloud storage.

The trade-off is that links expire, require a click, and sometimes get stripped by corporate mail filters. For anything that must survive in the recipient’s mailbox (a signed contract, a receipt), a compressed attachment under the limit is the safer choice.

Questions

Why does Gmail say my 24 MB file is too big?

Because the limit is for the whole message. A signature image, an inline logo, and a second attachment all count. Remove the extras, or bring the main file down to 20 MB to leave room.

Will compressing a video for email ruin it?

At 20 MB, a one- or two-minute clip at 720p or 1080p looks fine on a phone or laptop. A ten-minute clip will not; at that length the bitrate has to fall too far. Trim, split, or send a link instead.

Can I send a file larger than 25 MB if I zip it?

Only if it is the kind of file zip compresses well, such as documents or spreadsheets. Media files are already compressed and barely change. Gmail applies the limit to the zip’s size, so check it in Finder before attaching.