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The Humanness Index™
Built by VapiGitHub

The Humanness Index™

The open benchmark for how human voice AI sounds, so you can pick the model that passes. Built by Vapi.

MethodologyGitHubContactvapi.ai

Code is Apache-2.0. Standings data is CC BY 4.0. Audio clips and source voices are licensed recordings, all rights reserved. Provider logomarks belong to their respective owners and are used nominatively. “The Humanness Index™” name and logo are Vapi trademarks; see TRADEMARKS.md.

  1. Humanness Index™
  2. Murf

Humanness Index™ · Provider

Murf

Murf

murf.ai

Murf offers speech APIs for conversational agents and studio narration.

Best ranked model
#15 Falcon 2.1
Humanness
71

Standings as of Oct 27, 2026, 17:12 UTC

Murf
Models on the Index
1
Languages
—
Price / 1M chars
$10
Visit Murf

Murf models on the Humanness Index™

RankModelHumannessLatencyLanguagesPrice / 1M chars
#15Falcon 2.171117 ms34$10

Compare against the full Humanness Index™ rankings

About Murf

Murf offers speech APIs for conversational agents and studio narration. Falcon 2.1 is its streaming model; Gen2 serves studio voiceovers. The Index evaluates Falcon 2.1 with the same licensed source voices as the rest of the field.

Sources: murf.ai

Shared voices

Murf Instant Voice Cloning creates private workspace voices from short reference recordings. The four Index clones use licensed recordings of Clara, Emma, Godfrey and Nelliot. Cloning access must be enabled on a Murf workspace before these endpoints can be used.

Sources: murf.ai

Murf stats

Price / 1M chars
$101
  1. murf.ai/api/docs/text-to-speech-models/falcon-2-1 (checked 2026-10-27) Falcon 2.1 public API rate: $0.01 per 1,000 characters, equivalent to $10 per 1M. Workspace agreements may differ. Instant cloning requires workspace enablement.

Other providers on the Index

ElevenLabsElevenLabsBest ranked model #1 · Eleven v3CartesiaCartesiaBest ranked model #12 · Sonic 3.6xAIxAIBest ranked model #3 · Grok TTSMiniMaxMiniMaxBest ranked model #4 · Speech 2.8GradiumGradiumBest ranked model #24 · Gradium TTSCanopy LabsCanopy LabsBest ranked model #6 · OrpheusInworldInworldBest ranked model #9 · TTS-1.5-maxSmallest.aiSmallest.aiBest ranked model #22 · Lightning v3.1NeuphonicNeuphonicBest ranked model #23 · neu_hqSpeechifySpeechifyBest ranked model #2 · Simba 3.2Fish AudioFish AudioBest ranked model #8 · S2.1-ProHumanHumanBaseline reference · Humanness 100

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Find the most human-sounding voice for your agent.

Compare the models in blind tests, read the methodology, or get in touch.

Read the methodologyStar on GitHub

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