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How to send a string larger than 25MB through Gmail

Gmail caps attachments at 25MB. Here's the Image to Base64 workflow that gets your file under the limit in seconds, with no quality nightmare.

Tool:Image to Base64

It happens more often than you'd think: a string just over the Gmail attachment limit, and you have to send it now.

Gmail's hard cap is 25MB per outgoing message. Gmail offers a Drive link automatically for files between 25MB and 10GB. Anything bigger gets rejected — sometimes silently, more often after you've waited 30 seconds for the upload bar to crawl. The fix is to bring the string below that threshold before you hit Attach.

Launch the tool: Image to Base64 — Everything happens locally in your browser — your file never leaves your device.

Why this happens

Strings grow for predictable reasons — embedded images at full camera resolution, fonts shipped twice, scanned pages saved at 600 DPI, video clips that were never meant for email. The original was fine for archiving, but it isn't shaped for email. Here's the practical workflow.

How to bring a string under 25MB

  1. Open Image to Base64 in any modern browser. Nothing installs.
  2. Drag the string onto the drop zone. Multiple files work too; Image to Base64 processes them in a single pass.
  3. Pick a compression preset. "Balanced" is the right answer 95% of the time — visually identical output, file size cut by 50–80%.
  4. Wait for processing — usually under five seconds for a string smaller than 50MB.
  5. Download the result. It lands in your default downloads folder under the original filename, suffixed.
  6. Attach the smaller version to Gmail and send. The size badge in the attachment row should now read well below 25MB.

If you have a stack of strings to send to the same person, drop them in together — Image to Base64 handles a batch in one click, then you attach the whole folder.

What if it's still too big?

A few strings resist compression — usually because they're already aggressively compressed, or they're video / audio at high bitrate. Two reliable next moves:

  • Trim or split. If the string is content-rich, sending half today and half tomorrow often beats forcing it into one attachment.
  • Switch to a cloud link. Gmail itself will offer "10GB via Google Drive link" once you exceed the limit. Google Drive, OneDrive, Dropbox, and WeTransfer all give you a copy-paste link that bypasses every mail provider's cap.

Try it now

Image to Base64 →

Free, no account required, no watermark.

Frequently asked questions

Is there a way to do this from my phone?

Yes — open Image to Base64 in mobile Safari or Chrome and drop the string from your photo library or Files app. The flow is identical to desktop, just with bigger taps.

Why does Gmail reject files over 25MB?

It's a server-side rule, not a client setting. Gmail offers a Drive link automatically for files between 25MB and 10GB.

Will the recipient be able to tell the string was compressed?

Usually not. The "Balanced" preset on Image to Base64 targets visually indistinguishable output. Only a side-by-side pixel comparison would reveal the difference, and recipients almost never do that.

Does Image to Base64 upload my string to a server?

No. Image to Base64 runs entirely in your browser using WebAssembly. The string never leaves your device — there is no server to send it to.

Related guides

Ready to try it?

Launch the tool: Image to Base64. No upload, no signup, no daily limit.

Last reviewed May 2026. File-size limits, portal requirements, and software defaults change over time — always verify with the destination platform before uploading time-sensitive documents. References to third-party services and products are for descriptive purposes only and do not imply any partnership or endorsement.