Free SMS APIs and Trial Credits
Which SMS and messaging APIs a startup can test or send with for free today, how much trial credit they give, who it can reach, which channels it covers, whether a card is needed and what paid messages cost, read from each provider's own page.
Free allowances read on each provider's own pages, all checked on or after . Messaging providers change their trial credit and rules often: confirm the terms on the provider's page, and your destination country's rules, before you send.
SMS and messaging APIs a startup can try for free today include Twilio (100 SMS, 75 voice minutes, 30-day trial), Firebase (First 10 SMS a day not billed), Plivo ($10 in free credits), Prelude (Free test credits, amount not stated), and Bandwidth (3,000 trial credits, one US number). Each of the 10 free allowances below links to the provider's page that states it, with its main limit, the channels it covers, whether a card is needed and what paid messages cost.
Sign-in codes, order updates and reminders all go out as text messages, through an SMS API. Most messaging APIs give free trial credit to build and test with, and phone verification services give a free allowance too.
The headline rarely tells you how far it goes. Trial credit often reaches only phone numbers you have verified, adds a trial prefix to messages, or expires after a few weeks, and production SMS in the US needs registration either way. Each API below shows what is free, its main limit, the channels it covers, whether a card is needed and what paid messages cost, quoted from the provider's own page with the date we read it.
Which APIs we picked and the order they appear in are our editorial choices; the terms are the providers'. Some of these providers pay us a referral commission when someone signs up through our link: those links are labeled, and they play no part in which APIs are listed or where.
SMS and voice APIs with free trial credit
Programmable SMS, voice and WhatsApp, with free credit to test before you pay per message.
- 1
Twilio
Trying SMS, voice and OTP before paying
Twilio's trial gives 100 SMS messages and 75 voice minutes with no card, but it sends only to verified numbers. Paid SMS starts at $0.0083 a message.
- Payment card
- No card needed (source: twilio.com)
- 2
Plivo
Startups testing SMS, voice or WhatsApp on a small credit
Plivo gives $10 in free credits with no credit card required. Its SMS page lists US long-code SMS at $0.0077 per message.
- What's free
- $10 in free credits (source: plivo.com)
- Payment card
- No card needed (source: plivo.com)
- Paid messages
- $0.0077 per US long-code SMS (source: plivo.com)
Start free at PlivoTerms read on plivo.com on Plivo: the free allowance and how to start Plivo Startup Credits Program: what startups get - 3
Bandwidth
Developers who want a US number and voice or SMS testing
Bandwidth Build gives 3,000 trial credits for voice or messaging with no credit card to start, plus one US number. Its pricing page lists US 10DLC messaging at $0.004 a message.
- Payment card
- No card to start (source: bandwidth.com)
- Paid messages
- $0.004 per US 10DLC message (source: bandwidth.com)
Start free at BandwidthTerms read on bandwidth.com on Bandwidth: the free allowance and how to start - 4
Vonage
Developers who want a card-free start on voice and SMS
Vonage's pricing page offers free credit with no credit card required, without stating the amount. SMS prices start as low as $0.0086 a message.
- Payment card
- No card needed (source: vonage.com)
- Paid messages
- From $0.0086 per message (source: vonage.com)
Start free at VonageTerms read on vonage.com on Vonage: the free allowance and how to start Vonage for Startups: what startups get - 5
Infobip
Teams testing several channels before any paid commitment
Infobip's trial gives free credits on each channel, which as a guide cover up to 100 messages, and a self-signup trial sends only to verified recipients.
Start free at InfobipTerms read on infobip.com on Infobip: the free allowance and how to start Infobip Startup Tribe: what startups get - 6
Textmagic
Small teams sending SMS and email from a prepaid balance
Textmagic starts a new account with a free test balance, and texting needs a dedicated virtual number for an extra fee. SMS starts at 4.9 cents a message on its 1,000 SMS pack.
Start free at TextmagicTerms read on textmagic.com on Textmagic: the free allowance and how to start - 7
ClickSend
A quick two-week test of SMS and the API
ClickSend gives a small A$2 trial credit to new accounts, which expires after 14 days and can be used to test its API.
Start free at ClickSendTerms read on help.clicksend.com on ClickSend: the free allowance and how to start - 8
Sinch
Developers who need a quick test on Sinch APIs
Sinch's trial account gets a test credit of $2 USD for US accounts, and it can send unrestricted SMS only to your own verified numbers.
OTP and phone verification APIs with a free allowance
Phone verification and one-time codes, with a free allowance to start.
- 1
Firebase
Apps already on Firebase that need phone sign-in codes
Firebase does not bill the first ten SMS a day for phone sign-in, but verification SMS needs the pay-as-you-go Blaze plan.
Start free at FirebaseTerms read on cloud.google.com on Firebase: the free allowance and how to start - 2
Prelude
Teams evaluating OTP verification with test numbers
Prelude's home page offers test numbers or free credits for testing. The amount of free credit is not stated.
Communications startup programs
Programs from messaging companies that give startups credits on paid usage.
Also useful for voice, speech and communications APIs
Referral links, picked for fit and ordered by fit (70%) and what a signup earns us (30%), at no cost to you. They never change this page's ranking.
Compare the top options
How this comparison is built
The list covers SMS, voice and verification APIs a founder can use for free today without applying to a program. The order and the "best for" notes are our editorial reading of each API's terms. Every term comes from the API's own pricing or help page on the date shown, never from a third-party list; follow each link for the full conditions. Trial credit that only reaches verified numbers, or adds a trial prefix, can matter more than the headline, so the comparison quotes those limits wherever the provider states them. Some of these APIs pay StartupPerks a referral commission, and their links are labeled as referral links; that decides neither whether nor where a API appears, and no API pays for a placement on this page.
Read the full methodologyCommon questions
What is the best free SMS API?
It depends on what you test. By the terms each provider states, Twilio's 30-day trial includes 100 SMS and 75 voice minutes to verified numbers, Plivo gives $10 in free credits, Bandwidth 3,000 trial credits with one US number, and Sinch a $2 test credit for US accounts.
Is Twilio free?
Twilio's free trial lasts 30 days with 100 SMS and 75 voice minutes, sent only to verified numbers. Paid SMS starts at $0.0083 per message sent or received.
Is there a free OTP SMS service?
Firebase does not bill the first 10 phone verification SMS a day, though phone sign-in needs its Blaze plan, and Prelude gives free test credits to start.
Can I send SMS to any number on a free trial?
Usually not. Twilio's and Infobip's trials send only to verified recipients, and Sinch's test credit goes to your own verified numbers.
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