SMS character limit
A standard long-code SMS holds 160 GSM-7 septets or 70 Unicode code units. Longer texts use parts of 153 septets or 67 code units, and each part is billed as a message. The five providers we score publish maxima from 1,530 to 3,200 GSM-7 characters.
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SMS character limits by provider
| Provider | One text | Per part of a longer text | Maximum a message | Source |
|---|---|---|---|---|
| Vonageaccepts up to 3,200 characters; advises no more than six parts, as not all carriers accept longer | GSM-7 160UCS-2 70 | GSM-7 153UCS-2 Not stated | GSM-7 3,200UCS-2 Not stated | Documentation |
| Sincha message body of up to 2,000 characters | GSM-7 160UCS-2 70 | GSM-7 153UCS-2 Not stated | GSM-7 2,000UCS-2 Not stated | Documentation |
| Twilio | GSM-7 160UCS-2 70 | GSM-7 153UCS-2 67 | GSM-7 1,600UCS-2 700 | Documentation |
| Plivo | GSM-7 160UCS-2 70 | GSM-7 153UCS-2 67 | GSM-7 1,600UCS-2 737 | Documentation |
| Telnyx10 segments per message | GSM-7 160UCS-2 70 | GSM-7 153UCS-2 67 | GSM-7 1,530UCS-2 670 | Documentation |
Both encodings are shown. Sorted by the GSM-7 maximum, highest first.
The accepted maximum length and the billed segment count are different tasks. A message can sit under the provider maximum and still bill as multiple segments. Use the SMS segment calculator to estimate segment cost.
License. Creative Commons Attribution 4.0 (CC BY 4.0). Reuse the table freely, with credit to SMS Comparison and a link to this page.
What the SMS character limit is
A single SMS carries 140 bytes of user data, and the encoding decides how far that goes. GSM-7 spends 7 bits a character, so the arithmetic Plivo publishes gives (140 bytes x 8 bits) / 7 bits = 160 characters. Unicode SMS uses 16-bit code units, so the same 140 bytes hold 70 units.
One non-GSM-7 character switches the entire message. Telnyx states that a single emoji or curly quote moves the whole text to UTF-16, cutting single-part capacity from 160 GSM-7 septets to 70 code units. Unicode explains that UTF-16 uses one or two 16-bit code units per code point, checked October 28, 2026. The calculator counts those units and keeps surrogate pairs together. 10 GSM-7 extension characters, including the euro sign, the curly brackets and the backslash, count as two each under 3GPP TS 23.038.
Why a long text stops short of the maximum
Each provider publishes its own ceiling for one message, read from its documentation on September 28, 2026. Twilio accepts 1,600 GSM-7 characters or 700 UCS-2. Plivo accepts 1,600 GSM-7 or 737 UCS-2. Telnyx caps a message at 10 segments, which is 1,530 GSM-7 or 670 UTF-16 characters. Sinch accepts a message body of up to 2,000 characters. Vonage accepts up to 3,200 characters, the highest of the five.
The published maximum is not a promise that carriers deliver it. Vonage advises no more than six parts, because not all carriers accept longer messages. Telnyx caps a message at 10 segments. For the count of parts your own text produces and what those parts cost at your volume, use the SMS segment calculator.
SMS character limit questions
Does a long text cost more?
Yes. Vonage states you are charged for each SMS part in a concatenated SMS, so a 320-character GSM-7 text bills as three messages. For per-part pricing, see SMS gateway prices.
Are MMS messages limited the same way?
No. Telnyx states that MMS and RCS messages use UTF-8 and are not affected by the 160 or 70 character limits.
Why does my text say it is too long to send?
Your provider's own maximum or a carrier limit applies. Vonage advises six parts maximum; Telnyx caps at 10 segments. Shorten the text or remove the emoji that forced UCS-2.
Why did one emoji cut my limit from 160 to 70?
One non-GSM-7 character switches the entire message to the 16-bit encoding, so the same 140 bytes hold 70 code units instead of 160. Telnyx documents this behavior.