SMS & MMS File Size Limits

Carriers cap how large a media attachment can be on a text message, and the cap depends on the recipient's carrier — not just yours.

Recommended limit

Keep attachments under 500 KB to reliably deliver across all major US carriers. Carrier maximums technically run a bit higher (roughly 0.6–1.5 MB depending on the carrier and number type), but staying well under that gives you margin so a slightly larger file doesn't fail unpredictably on one carrier while working on another.

Numbers using toll-free or short-code sending can generally handle larger files, up to about 5 MB.

What happens if you go over

An oversized attachment typically causes the message to fail delivery entirely, rather than sending a smaller or compressed version automatically. If you're seeing delivery failures on messages with attachments, check the file size first — it's one of the most common causes.

Practical tips

• Compress images before attaching them rather than sending original camera-resolution files.
• If you need to share something larger than a text can reliably carry (a PDF, a long video), send a link to it instead of the file itself.