SMS is text-only, 160 characters, cheapest, and near-instant — the channel for reminders, flash offers and two-way conversation. MMS carries images, GIFs and video plus ~1,000 characters for a higher per-message price — the channel for anything where the brand or the offer needs to be seen. The working rule: open the relationship with MMS, sustain it with SMS, and return to MMS when the content earns it. Here is the full comparison behind that rule.
Last reviewed: 5 August 2026.
| SMS | MMS | |
|---|---|---|
| Content | text only | image / GIF / video / audio + text |
| Length | 160 chars (GSM-7), 70 with emoji/unicode | ~1,000+ chars + subject line |
| Long-message billing | per 153-char segment — a 480-char SMS bills as 3+ messages | one message, one price |
| Media size (AU practice) | — | design ≤500–600 KB; ≤150 KB when time-sensitive |
| Relative cost | lowest | several × SMS per message — but see billing note above |
| Delivery speed | near-instant | slightly slower (media download) |
| Open rate | ~98% (channel-level) | ~98% (channel-level) |
| Click-through observed | strong | up to 60% on personalised campaigns |
| Coupon redemption observed | good | 14.5% vs <1% for equivalent email |
| Best cadence | higher (monthly+) | lower (quarterly-ish) |
| Two-way | yes, from a dedicated number | yes, from a dedicated number |
| Compliance | identical — Spam Act applies to both | + identify brand in media and text layer |
Comparing per-message price alone is the classic mistake. The comparison that decides budgets is cost per outcome:
A campaign that costs 4× more per message but redeems at 14.5% against a sub-1% email baseline — or clicks through at 60% — is not the expensive option. Price the redemption, not the send.
And one structural subtlety: long SMS is billed per 153-character segment, so a personalised 3-segment SMS can approach MMS pricing while carrying no media. If the copy is long anyway, MMS is often the better buy.
The programs that perform treat this as sequencing, not a choice: an MMS (with vCard) establishes the brand identity in the handset; SMS carries the routine cadence under that established name; MMS returns for the moments that deserve it. Both run from the same dedicated number, the same consent base and the same compliance posture.
Is MMS worth the extra cost over SMS? When the message benefits from being seen — offers, launches, gift cards — yes: personalised MMS campaigns have recorded 60% click-through and 14.5% redemption, figures SMS text alone doesn't reach. For simple informational touches, SMS remains the right buy.
How many characters can an SMS contain? 160 GSM-7 characters, or 70 if the message contains unicode (including emoji). Longer messages send as concatenated segments of 153 (or 67) characters each, billed per segment.
Do MMS and SMS have the same open rate? Broadly yes — around 98% at channel level, because both land in the native inbox. The difference shows in engagement after the open: click-through and redemption favour MMS when creative is personalised.
Can I send both from the same number? Yes, and you should — a consistent dedicated number (with an MMS-delivered vCard) is how the brand accumulates recognition in the recipient's phone.
intouch by MobileDigital runs SMS and MMS from one platform, one number and one consent base — with per-recipient personalised visuals for the MMS moments.