MMS image size, file size and format — the complete guide to 800×800, 230KB and JPG vs PNG vs GIF (Hong Kong, 2026)

Key takeaways

• Carriers cap the whole MMS — text plus image combined — at 230KB, not the image on its own.
• Images must be no larger than 800×800 pixels; JPG is recommended, though PNG can come out smaller for large flat-colour areas.
• GIF is allowed, but animation frames eat the budget fast, and whether it animates depends on the recipient’s messaging app.
• Plain text is tiny — about 30KB for 10,000 Chinese characters — so the budget is really for the image.
• Resize to 800×800 first, then export JPG at quality 70–80, and you will usually land inside the limit.

Image ready and want to see it on a phone? Start a free trial: trial credit on signup, upload in the dashboard, preview the total size and send to your own handset, no credit card required. Full service details on MMS marketing.

Designers rarely ask “what is MMS”. They ask three practical things: what size, how big a file, and does GIF work. This article answers all three, then gives export steps and a pre-upload checklist. If you are still weighing MMS against SMS, start with What is MMS.

The three questions people search for

What size should an MMS image be?

On the UFOSEND platform, a single image must be no larger than 800×800 pixels. That is an upload limit, not a recommendation — anything larger is rejected.

Square is the safest ratio. Both iPhone and Android messaging apps shrink the image into a preview inside the chat bubble; a tall portrait image gets cropped harder, and a wide landscape one shrinks to a sliver. 800×800 displays fully on almost every phone with the headline readable without tapping.

How big can an MMS image be?

The whole MMS — text plus image — must stay under 230KB. This is the most misunderstood point: the cap is on the message, not the image.

Plain text barely counts. Ten thousand Traditional Chinese characters come to about 30KB; a typical few hundred characters of promotional copy is under 2KB. So in practice you have 200KB or more for the image.

Can you send a GIF by MMS?

Yes. Supported formats are JPG, PNG and GIF.

Two practical limits, though. First, an 800×800 GIF with a dozen frames blows past 230KB easily, because every frame counts. Second, whether it animates depends on the recipient’s phone: iPhone Messages generally plays it, some Android messaging apps show only the first frame. If you use animation, design the first frame as a standalone poster and test on several of your own handsets.

Why 230KB?

MMS does not travel over the SMS channel. It goes through the carrier’s Multimedia Messaging Service Centre (MMSC), and each carrier has its own cap per message. 230KB is the safe value that passes every local network reliably.

What matters is what happens when you exceed it: the message is not “compressed and sent”, it is rejected. You see a failure status in the delivery receipt (DLR), and the message is still billed. So size is handled before upload, not after send.

A three-zone layout for 800×800

An MMS preview on a phone is usually half to two-thirds of the screen width, so design for “still readable at one third the size”:

• Top third: the hero. One product or one scene, never a collage.
• Middle: the headline. At least 48px on the 800×800 original, bold, on a solid background. A phone thumbnail leaves roughly a third of that; below 48px it is effectively unreadable.
• Bottom third: offer and action. Discount, date, store or link.

Fine print — terms, how to unsubscribe — goes in the MMS text field, not in the image. Text costs almost nothing in the budget and stays copyable and searchable.

Export steps in Canva or Photoshop

1. Set the canvas to 800×800 px. Do not design at 1080×1080 and scale down; you will misjudge type sizes.
2. Put text on solid colour. Thin type over a photo turns to mush at thumbnail size.
3. Export JPG at quality 70–80. This usually lands at 100–200KB. If the image has large flat areas (a plain background with big type), export PNG as well and keep the smaller one.
4. Check the file size in the OS. Design tools show estimates; trust Finder or File Explorer.
5. Upload and preview the total. The dashboard shows text plus image combined and warns before send if you are over.

There are only three common rejection reasons: image over 800×800, format outside JPG/PNG/GIF, and text plus image over 230KB.

How iPhone and Android differ

The same MMS looks different on different phones, and it is easier to design once you accept that:

• iPhone: the image is the body of the message and the text sits beneath it. The image downloads automatically (given a data connection).
• Android: varies by brand and messaging app. Some show a “download” button first and reveal the image only on tap; others auto-download. The order of text and image can differ too.
• Roaming: the image download usually needs mobile data; with data roaming off the user sees only the notification. See Do you still receive SMS/MMS abroad?.

So the headline always lives in the image, while the critical details (date, promo code) appear once in the image and once in the text field. For troubleshooting undelivered or undownloadable images, see MMS charges, non-delivery and how it differs from SMS.

Pre-upload checklist

• Image ≤ 800×800 px
• Format is JPG, PNG or GIF
• Text + image ≤ 230KB (as shown in the dashboard preview)
• Headline ≥ 48px on solid colour
• Date and promo code appear in both the image and the text field
• Promotional messages carry an unsubscribe method and sender details — see the Hong Kong marketing message compliance checklist
• Sent to one iPhone and one Android of your own first

FAQ

Can I send a portrait 800×1200?
No. Neither side may exceed 800px. Handle portrait compositions with whitespace inside 800×800.

Is WebP or HEIC accepted?
No. Convert to JPG or PNG on export.

My image is only 150KB — why is it over?
Look at the total. A long block of terms in the text field, or a GIF with many frames, can push the combined size past 230KB.

Will compressing to 230KB look blurry?
An 800×800 JPG at quality 70–80 is usually indistinguishable to the eye, and the phone displays it smaller than the original anyway.

The most reliable check is to upload and send one to your own phone — start a free trial, trial credit on signup, no credit card required. If you would rather have us lay it out, contact us.