Why yes, people still use telephones. There are now several voice APIs that help you tap into that network programmatically. You can send and receive calls, use touchtone input, read text, and record voice, among other features.
Your applications can use voice APIs to send alerts, create conference calls, and build call centers, among many other potential use cases. You can reserve your own phone numbers and typically you pay a small price per minute of usage, which means voice APIs are an affordable value-add or, like SMS, can be the entire application.
Top Voice APIs Comparison
| Plivo | Tropo | Twilio | |
|---|---|---|---|
| DX Index | 9 | 7 | 9 |
| Gorilla Index | 2 | 2 | 10 |
| Year founded | 2011 | 2009 | 2007 |
| Employees | 43 | 81,812 | 536 |
Quick Takes
- Use Plivo for… an excellent Twilio alternative
- Use Tropo for… the security of a large parent company
- Use Twilio for… its strong developer experience and longevity
Use Cases
- Call forwarding: give yourself a local number everywhere your customers live without needing a table full of phones. Just redirect each number to your office phone, mobile phone, or to whichever team members is on duty.
- Anonymized numbers: if you’re allowing two or more members of a community to call each other, they may not want to share numbers if they’ve just met. You can be the arbiter who safely makes the connection.
- Decision trees: help determine user’s needs, or route them to the right place, by adding a touchtone menu to your phone number.
Market
Unlike with SMS APIs, creating Voice APIs does not require connecting to the many disparate wireless companies. Instead, providers connect their VOIP service to the existing telephone networks.
Because it is less complex than SMS, there are many more providers, though only three have been singled out for this comparison. As with SMS, the market is dominated by early entrant Twilio. The San Francisco mega-startup has a keen understanding of who developers are and what they want.
That said, Plivo is on par with Twilio for developer experience and Cisco’s acquisition of Tropo makes it more capable of serving the enterprise market Twilio needs to scale.
Developer Experience
“Press 1 for…” may be the bane of the customer service experience. Maybe the typical call center pain stems from how difficult those systems used to be to create. Now we have services like these Voice APIs and you can use them to improve how your customers interact with your application via a telephone.
Twilio is a shining example of developer experience, even outside this category. Surprisingly, we found them nearly matched by Plivo, and Tropo not too far behind. Twilio’s embracing cURL examples, multiple programming languages, and sample application quickstarts make it a powerful choice to get started right away.
Programming Language Support
| Front-end | |||
|---|---|---|---|
| Plivo | Tropo | Twilio | |
| JavaScript | |||
| Mobile | |||
| Plivo | Tropo | Twilio | |
| Android | |||
| iOS | |||
| Traditional SDKs / Client Libraries | |||
| Plivo | Tropo | Twilio | |
| Go | |||
| Java | |||
| .NET | |||
| Node | |||
| Perl | |||
| PHP | |||
| Python | |||
| Rails | |||
| Ruby | |||
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