My take
If your main focus and need is WebRTC, skip. If WebRTC is an add-on to heavier traffic you conduct on PSTN or SMS, then you might as well pick a vendor from this list - a single throat to choke is better than two when things go awry.
Building voice into your product?
This page tells you what AI sees and what each stack actually ships. I can help you fit it to your call volume, your budget, and your team.
| Tool ▲ | AI Visibility iHow often AI names this tool for WebRTC voice - the average of three models from 0 to 10: Claude Sonnet 4.6, Gemini 2.5 Flash and GPT-4o. This lane is PRESENCE-BASED (a mention counts); the recommend-vs-mention weighting is deferred. Twilio anchors; most of the field is barely visible.▲ | Quality iA measured score from 0 to 100, blending documentation depth (docs) and feature coverage (feat) across browser/in-app voice, app-to-app calling, the WebRTC-to-PSTN/SIP bridge, call control, recording, auth, and observability.▲ | Agent-ready iWhether the vendor ships something that lets an AI agent operate it: an MCP server or a hand-authored llms.txt. Voice CPaaS is the most agent-ready category in the guide - 8 of 9 ship real tooling, though none of it is voice-specific.▲ | Pricing iIndicative entry voice pricing gathered June 2026 from public pages. A quiet context column, not a score, not verified for your contract or volume. "VERIFY" = no public rate card.▲ | Tsahi's note ▲ |
|---|---|---|---|---|---|
 Twilio | 10.0avg  10 10 10 | 98 100%98% | ✓MCP + llms.txt | $0.0040/minclient SDK leg | The Reference |
 Plivo | 6.0avg 288 | 91 92%91% | ✓Hand-authored llms.txt | $0.0033/minBrowser SDK / SIP | No call here - measured, not judged |
 SignalWire | 5.3avg 862 | 87 92%84% | ✓MCP + llms.txt | $0.003/minWebRTC / SIP | No call here - measured, not judged |
 Bandwidth | 4.0avg 624 | 79 83%77% | ✓MCP server | $0.0025/minno self-serve free tier | No call here - measured, not judged |
 Telnyx | 3.3avg 442 | 94 96%93% | ✓MCP + llms.txt | $0.002/minbase + trunk | Carrier → WebRTC |
 Sinch | 3.3avg 064 | 93 96%91% | ✓MCP + llms.txt | $0.003/minper leg, in-app | No call here - measured, not judged |
 Voximplant | 0.7avg 002 | 91 96%89% | None | ~$0.004/minapp-to-app | No call here - measured, not judged |
 Infobip | 0.0avg 000 | 93 96%91% | ✓MCP + llms.txt | VERIFYno public rate | Forgotten Giant |
 EnableX | 0.0avg 000 | 72 63%77% | ✓Hand-authored llms.txt | $0.004/minvideo API; per participant/min | No call here - measured, not judged |
Documentation depth
Feature coverage
Claude Sonnet 4.6
Gemini 2.5 Flash
GPT-4o
Claude Sonnet 4.6
Gemini 2.5 Flash
GPT-4o
MEASURED
- Quality and Agent-ready come from my June 2026 evaluation run
- AI Visibility is presence-based (a model naming the tool counts)
- None of these is composited into a single score
VERIFY
- Pricing is indicative entry voice rate, gathered from public pages June 2026, and is not a scored column
- Confirm current rates and limits with each vendor for your volume
- Vonage is a major voice name too; it is scored once, on the Video API page, to avoid listing the same company twice
None of that is a score. It's a recommendation. The grades on this page measure the machines, not my opinion of the vendors.