SMS & Voice APIs · 2026 reliability ranking
Most Reliable SMS & Voice APIs (2026)
We ranked 15 SMS & voice APIs by real-world reliability over the last 90 days, using 296 status page incidents and our own around-the-clock uptime checks. An SMS or voice API carries a business's appointment reminders, login codes, order updates and customer calls, so when the provider has problems those messages arrive late or not at all and customers can't log in, confirm bookings or reach the business. The software that calls the API usually keeps running and doesn't show an error, so a delivery outage can go unnoticed for hours. Problems at a single mobile carrier are common across all providers; outages of the provider's own API or messaging platform are rarer and affect every recipient.
Last updated Nov 2, 2026 · How we score
| # | Vendor | Score | Uptime (90d) |
|---|---|---|---|
| 1 | PlivoPlivo is a cloud communications platform offering SMS, voice, SIP trunking and verification APIs.Visit site ↗ | 99.6 | 100% |
| 2 | SignalWireSignalWire is a Tampa, Florida-based programmable communications platform offering voice, SMS, video and AI agent APIs, built by the creators of FreeSWITCH.Visit site ↗ | 92.1 | 99.94% |
| 3 | TelesignTelesign is a provider of SMS, voice and phone-number verification and identity APIs, owned by Belgian telecom group Proximus.Visit site ↗ | 89.4 | 99.91% |
| 4 | TextmagicTextmagic is a Tallinn, Estonia-based business text messaging service with a web app, email-to-SMS and an SMS API.Visit site ↗ | 86.2 | 99.82% |
| 5 | Africa's TalkingAfrica's Talking is a Nairobi-based communications API provider offering SMS, USSD, voice and airtime APIs across African markets.Visit site ↗ | 78.7 | 99.80% |
| 6 | InfobipInfobip is a Croatia-based cloud communications platform offering SMS, voice, WhatsApp, email and customer engagement APIs.Visit site ↗ | 73.1 | 99.73% |
| 7 | BirdBird, formerly MessageBird, is an Amsterdam-based platform offering SMS, WhatsApp, voice and email APIs alongside marketing and CRM tools.Visit site ↗ | 61.7 | 99.47% |
| 8 | SinchSinch is a Stockholm-based communications platform offering SMS, voice, verification and conversational messaging APIs.Visit site ↗ | 61.1 | 99.40% |
| 9 | Vonage Communications APIsVonage Communications APIs, formerly Nexmo, are the SMS, voice, video and verification APIs of Vonage, a subsidiary of Ericsson.Visit site ↗ | 53.7 | 99.10% |
| 10 | BandwidthBandwidth is a Raleigh, North Carolina-based communications platform and CLEC offering voice, messaging, 911 and phone number APIs over its own US network.Visit site ↗ | 33.7 | 97.18% |
| 11 | TwilioTwilio is a San Francisco-based cloud communications platform offering SMS, voice, WhatsApp, email and verification APIs.Visit site ↗ | 30.6 | 96.05% |
| 12 | TelnyxTelnyx is a Chicago-based communications platform offering voice, SMS, SIP trunking, wireless IoT and AI voice agent APIs on its own private network.Visit site ↗ | 28.6 | 92.61% |
SMS & Voice APIs reliability at a glance
- Across the 12 ranked SMS & voice APIs, average 90-day uptime is 98.58%. Reliability scores range from 99.6 (Plivo) to 28.6 (Telnyx).
- Together they published 296 incidents in the last 90 days, 45 of them partial or major outages.
- The typical vendor takes 5h 38m to resolve an incident. Infobip is fastest, at 39m on average.
- Twilio reported the most incidents (100 in 90 days).
What to check before you choose a SMS & voice API
- Separate platform outages from carrier notices. Every provider posts delivery delays to individual mobile networks; what matters is how often its own API, messaging queue or voice platform fails.
- Check the components you depend on: outbound SMS, inbound replies, delivery receipts, voice calling and the verification (one-time code) API can each fail on their own.
- If text messages are business-critical, such as login codes or appointment reminders, keep a second provider set up so you can switch when one is down.
- Make sure your application logs failed sends and delivery receipts, so you can see a delivery problem before customers tell you about it.
90-day uptime history
Each bar is one day. Hover a bar for that day's uptime and incidents.
1. Plivo
100% uptime · 1 incidents · avg resolve —2. SignalWire
99.94% uptime · 3 incidents · avg resolve 47m3. Telesign
99.91% uptime · 8 incidents · avg resolve 1h 27m4. Textmagic
99.82% uptime · 1 incidents · avg resolve 3h 44m5. Africa's Talking
99.80% uptime · 5 incidents · avg resolve 6h 12m6. Infobip
99.73% uptime · 25 incidents · avg resolve 39m7. Bird
99.47% uptime · 8 incidents · avg resolve 12h 38m8. Sinch
99.40% uptime · 20 incidents · avg resolve 4h 51m9. Vonage Communications APIs
99.10% uptime · 24 incidents · avg resolve 10h 44m10. Bandwidth
97.18% uptime · 67 incidents · avg resolve 5h 38m11. Twilio
96.05% uptime · 100 incidents · avg resolve 8h 16m12. Telnyx
92.61% uptime · 34 incidents · avg resolve 16h 24m- No incidents
- Degraded
- Partial outage
- Major outage
- No data
Being tracked (not ranked yet)
These vendors join the ranking once we have enough evidence: at least 14 days of data, and for vendors with a quiet status page (silent for a year, or for 90 days while their competitors report several incidents), 30 days of our own independent monitoring.
- AWS End User Messaging · quiet status page, awaiting our own monitoring
- ClickSend · quiet status page, awaiting our own monitoring
- Kaleyra · quiet status page, awaiting our own monitoring
Recent SMS & Voice APIs incidents
Global (Europe) - Partial Packet Loss
Affected: Global (Europe), Global (Europe)
Affected: API V2, API V1
Affected: SMS, APAC, SMS, Middle East & Africa
Number Portability Checker Incidentofficial update ↗
Affected: Number Porting
Delays with Messaging Webhooks, Mission Control Number and Porting ordering/configurations
Affected: US West Region, API V2, US East Region, US Central Region
Link Shortening Redirect Errors on Branded Domains
Affected: SMS
Affected: US, Australia, Asia (Beta), Middle East, Europe, Canada
Head-to-head comparisons
- Plivo vs SignalWire reliability
- Plivo vs Telesign reliability
- Plivo vs Textmagic reliability
- Plivo vs Africa's Talking reliability
- SignalWire vs Telesign reliability
- SignalWire vs Textmagic reliability
- SignalWire vs Africa's Talking reliability
- Telesign vs Textmagic reliability
- Telesign vs Africa's Talking reliability
- Textmagic vs Africa's Talking reliability
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Frequently asked questions
What is the most reliable SMS & voice API?
Based on the last 90 days of data, Plivo is the most reliable SMS & voice API we track, with a reliability score of 99.6/100 and 100% uptime.
How do you measure SMS & voice API reliability?
We poll each vendor's public status page every few minutes, record every incident, and run our own uptime checks against each vendor's login and customer-facing pages. Uptime (40%), incident frequency (20%), average time to resolve (20%) and transparency (20%) combine into one score out of 100.
How often are these rankings updated?
Continuously. Status pages and uptime checks run every five minutes and scores are recalculated several times an hour.
Can vendors pay to rank higher?
No. Sponsored placements are clearly labelled, shown separately from the rankings and never change a vendor's score.