How quickly can I send SMS messages?
Your Twilio SMS-enabled long code phone numbers can send SMS messages at a rate of one message segment per second. You can make requests to Twilio as fast as you like, and Twilio will queue the messages, releasing them at a rate of one message per the number of message segments in seconds. This means if your SMS message is under 160 characters and does not include any non-GSM characters, it has 1 message segment, and will be released at the rate of one message per second. If your SMS message has 3 segments, a single message will be released every 3 seconds.
On US and Canadian toll-free phone numbers, the rate limit is 3 message segments per second.
It is currently not possible to adjust this rate, but if you will be sending more messages, you can purchase additional numbers. Also please note that while Twilio releases messages to our carrier partner at this rate, your messages may be subject to mobile carrier filtering and can get blocked. You can read this FAQ to learn more.
Depending on what your use case is, a short code may be a better option for you. Short code messages can be released at the rate of 30 messages per second. Check out our short code FAQ or talk to our sales team to determine what is best for you.