Gmail, Outlook & Yahoo Attachment Size Limits (2026)

The Gmail attachment size limit is 25 MB for personal accounts. Outlook.com also allows 25 MB, Yahoo Mail allows 25 MB in total per message, and the Outlook desktop app applies a 20 MB limit to internet accounts such as Gmail and Outlook.com. Attachments are encoded before sending, which makes them about a third bigger, so a file well under the headline number can still fail. For photos, compressing them or sending a link is usually easier than fighting the limit.

Attachment limits by provider

Three points from the official pages are easy to miss:

• Outlook has two numbers. Microsoft's Outlook.com page gives 25 MB for attachments, while its page about the Outlook app says the limit for internet accounts such as Outlook.com or Gmail is 20 MB and "includes both the size of the attachment and the size of the email." If you use the desktop app, plan for 20 MB.
• Limits are per message, not per file. Yahoo is explicit that "the sum of all attached files in a single message" counts. Ten 3 MB photos are 30 MB, which is too much.
• The receiver's limit matters too. Yahoo's limit applies to incoming mail as well. If you send a 24 MB message from Gmail to a company with a 10 MB Exchange limit, it can bounce on their side even though Gmail accepted it.

How to check the total before you send

• Windows: select all the photos in File Explorer, right-click and choose Properties. The General tab shows the combined size.
• Mac: select the photos in Finder and press Option-Command-I to open one info window with the total.
• Phone: the easiest check is to try attaching. If the mail app warns you, or offers to send a smaller version, you are over the limit.

If the total is close to the limit, assume it will fail once encoded, for the reason explained next.

Why a 25 MB file fails at 19 MB

Email was designed for text, so attachments are converted into text before they travel. The standard method, Base64, is defined in the MIME specification (RFC 2045, section 6.8): every 3 bytes of your file become 4 text characters. That makes the attachment roughly 33% larger in transit, before counting line breaks and the message itself.

Work it backwards and the numbers line up with what people see:

Providers do not all document exactly how they measure, so treat this table as a guide rather than a rule. Microsoft's wording, that the limit covers the attachment plus the email, is the clearest hint. In practice, if your photos add up to more than about three quarters of the stated limit, expect trouble and shrink them or send a link.

Send photos as a link instead

A link sidesteps the attachment limit completely, because the email only carries a line of text. The recipient clicks the link and the photo opens in their browser. It also keeps their inbox small and works on any email app.

To send a photo as a link with PictureToLink:

1. Open the image uploader and drop in your photos. You can add up to 20 at once, each up to 25 MB, in JPG, PNG, WebP, GIF or AVIF.
2. Choose a format from the link menu. Share page is best for people: it opens a clean page with the photo on it. Use Copy all to get every link, one per line.
3. Paste the links into your email and send.

Each upload is compressed and has its location data and other metadata removed before it is stored, so you are not sending GPS coordinates by accident. You can choose to have images deleted automatically after 1 hour, 1 day, 7 days or 30 days, and you get a private delete link for each one. Otherwise an image stays online while people keep viewing it and is removed after 12 months without a view, so this is a sharing tool, not long-term storage.

Be aware that anyone with the link can see the photo. That is fine for holiday pictures and product shots, but not for passports, bank documents or anything private. Our guide to image links versus attachments covers when each is the better choice. If you are sending HEIC photos from an iPhone, export them as JPG first, as PictureToLink does not accept HEIC.