Infobip Voice API vs SIP.IO

Infobip Voice API provides programmable voice tools for mobile and web applications, including calls to landlines and mobile phones. Developers can use Calls API to build inbound and outbound applications and control calls over PSTN, WebRTC, or SIP. Available functions include programmable calls, voice messages, IVR with DTMF collection, click-to-call, number masking, and browser-based WebRTC. SIP trunking connects a PBX or SBC to Infobip, with static and dynamic inbound call-routing rules. Voice can also be used with Infobip Inbox, Customer Profiles, Chatbots, and Journeys, and calling is documented for WhatsApp and Viber. Speech tools support text-to-speech in more than 100 languages and accents, as well as speech capture and transcription. Native SDKs are supported for JavaScript, Android, and iOS. The service has no free plan, but offers a 60-day trial with limits: 15 outgoing calls or voice messages, 15 incoming calls, and 100 WebRTC calls. Trial phone calls require verified mobile numbers and are capped at five minutes. Recording and conferencing are add-ons; conferencing is required for calls with three or more participants.

SIP.IO is a programmable voice and cloud contact center platform for UCaaS, CCaaS, and Voice AI. Its listed services include business phone service and SIP trunking, alongside skills-based queues, agents, a wallboard, and reporting. Developers can embed a softphone in an app for browser-based WebRTC calls. Messaging includes SMS-to-email and inbound SMS webhooks, with webhook requests signed using HMAC. Call recording supports policy-based rules, pausing and resuming during a call, and playback through an audited API. Voice AI agents can escalate to a person; the platform also offers searchable call transcripts and AI summaries, with the option to use a customer's AI provider. SIP.IO lists managed, white-label Microsoft Teams Direct Routing with tenant setup by API. Its free tier includes trial credit, a test phone number, and access to call flows, queues, and contact center features without a credit card. Usage-based voice and number pricing is available by contacting SIP.IO; published rates are examples, not the final rate card. SIP.IO says it is ISO/IEC 27001 certified and that HIPAA and a Business Associate Agreement program are not offered.