How to attach a file in Gmail on Mac: browser steps, size limits and fixes

Gmail on a Mac runs in your browser

Google's computer help pages describe one version of Gmail, the web app at mail.google.com. The steps on this page use that version. Open it in Safari, Chrome, or another browser, then sign in with your Google account.

This matters because menus and buttons depend on the window you are in. If your screen looks different from these steps, check the address bar first. It should show mail.google.com. If it does not, you may be in a different mail app, and these steps will not match.

Attach a file in Gmail step by step

The attach step has one rule that trips people up. The Attach icon lives inside the message window, not on the inbox screen. Click Compose first, then look at the bottom of the window.

Once the message window is open, the rest takes only a few clicks. You click the paperclip, pick the file in the Mac file window, and click Open. The file name then appears in the message, with a Close icon beside it.

Pick several files in one message

In the file window, hold ⌘ and click each file you want. Then click Open. Gmail attaches every file you selected to the same message. Check the total before you send.

Check the file size limit before you attach

A personal Gmail account can send 25 MB of attachments in one message. Google's help page gives that figure. The limit covers the total, so two files that add up past 25 MB will not travel as normal attachments.

Work and school accounts use a different limit. Google says your Google Workspace administrator sets it. If you are not sure, ask your IT team before a large send.

Enterprise Plus is the exception. Google announced a 50 MB sending limit for those accounts on February 24, 2026, with incoming messages raised to 70 MB. Your admin has to turn it on. You have no setting for it yourself.

What happens when a file is too big

Gmail does not always stop an oversized file. If total attachment size goes past the limit, Gmail removes the attachment and adds it as a Google Drive link. Your recipient gets a link to the file instead of the file.

You can choose this route yourself. In the Compose window, click the Insert files using Drive icon at the bottom. Select your files. At the bottom of the page, choose Drive link or attachment, then click Insert.

Drive links have sharing options. Anyone with the link can get view, comment, or edit access, and they do not need a Google Account. If you pick More options, only the message recipients can open the file. Those people may still be blocked if they lack a Google Account or get the message through a mailing list.

Worked example: a PDF and a photo folder

Say you want to send a PDF and a zipped photo folder. Add their sizes together before you attach anything. If the total goes past 25 MB on a personal account, use Drive. Insert both files from Drive, choose Drive link, and click Insert.

Which file types Gmail blocks

Gmail blocks 54 file extensions as attachments. Google's list includes .exe, .dll, .dmg, .iso, .msi, .js, .bat, .jar, and .vbs. Google can change this list, so check the page before an important send.

• .exe and .dll are Windows program files.
• .dmg and .iso are disk image files, often used for app installers.
• .js and .bat are script files.
• .jar is a Java archive, and .vbs is a VBScript file.

Zipping does not get around this. Gmail blocks some types even when they are compressed, such as .gz or .bz2. It also blocks .zip or .tgz archives that contain a blocked file. Google's suggested fix is to upload the file to Google Drive and send it from there.

If Gmail blocks the whole message for security reasons, it shows this text: This message was blocked because its content presents a potential security issue. Google describes that text for blocked messages in general, so it may not name your file.

Remove an attachment before you send

Attached the wrong file? Click the Close icon to the right of its name. The file leaves the message. The original file on your Mac stays where it was.

Check the list after you remove something. Gmail can show several names in a row, and it is easy to miss one. Read each name before you click Send.

Turn on keyboard shortcuts to send faster

Gmail keyboard shortcuts need to be turned on before they work. Open Settings, choose See all settings, scroll to Keyboard shortcuts, select Keyboard shortcuts on, and click Save Changes.

After that, ⌘ Enter sends the message. Google's keyboard shortcut page lists that one. The same page does not list a shortcut for attaching files, so use the paperclip for that step.

Common mistakes that cause failed attachments

• Attaching an installer such as a .dmg file, which Gmail blocks.
• Zipping blocked files and expecting the archive to get through.
• Treating 25 MB as a limit per file. It applies to the whole message.
• Sending a Drive link to someone who needs a Google Account.
• Leaving the wrong file attached because the name was missed.

Most of these come down to one habit. Read the file names and the total size before you send.

Check the message before you send

Before you send, open each file yourself if you can. That catches a corrupt download before someone else does. Then read the names once more and confirm the recipient address.

If you also plan to send later, read how to schedule email in Gmail on Mac. It covers the Safari and Chrome steps for scheduled sends.

Where to go after the file is attached

If you sent the wrong file, the fastest fix is usually a short undo window. Read undo send in Gmail on Mac for the browser steps. Once the message is out, you cannot take the file back from the recipient.