Top Voice Cloning APIs of 2026: Evaluating Speaker Similarity, Consent Verification, and Cost per Million Characters

A stock voice only has to sound pleasant. A cloned voice has to sound like one particular individual—a far tougher standard. The seven voice cloning providers examined here take very different approaches to meeting it.

To test them, we captured a single 10-second reference recording and used it to create a clone on every platform. The side-by-side results are shown unlabeled below, letting you form your own judgment before seeing which name belongs to which sample. We then evaluate the four factors that determine real-world deployments: required reference audio, consent verification, commercial licensing, and language support.

How the 10-Second Test Works

The reference consists of 10 seconds from a single speaker in a quiet room, saved as a WAV file. Every platform reads the identical two sentences—one conversational, the other packed with numbers and a proper name. Each vendor's instant cloning pathway was used with default settings.

Two vendors required adjustments. Hume documents 15 seconds as its minimum, so its clone used the same speaker's audio extended to 15 seconds. ElevenLabs recommends 1 to 2 minutes for Instant Voice Cloning, meaning its 10-second clone falls short of official guidance.

Comparison at a Glance

| Provider | Reference audio (instant / pro) | Consent verification | Commercial license from | Languages | List price per 1M chars |
|---|---|---|---|---|---|
| ElevenLabs | 1–2 min recommended / 30 min minimum | Rights attestation for IVC; Voice Captcha for PVC | Starter, $6/mo | 70+ (Eleven v3) | $50 (Flash) to $100 (v3) |
| Cartesia | 10 s, up to 60 s on Sonic 3.6+ / 30 min | Permission required by terms | Pro, $5/mo | 44 | ~$37 to $50 |
| Inworld | 3–30 s / 10 min minimum (beta, English only) | Rights confirmation | Free On-Demand tier | 200+ languages and locales | $12.50 to $25 (TTS-2) |
| Gradium | 10 s / 30 min, 2 h recommended | Owner consent required by policy | XS, $13/mo | 5 | ~$36 to $58 |
| Fish Audio | ~10 s / 10–180 min | Live ownership check for pro clones | Plus, $15/mo | 83 | $15 per 1M UTF-8 bytes |
| Resemble AI | 10 s / 10–25+ min | Verifiable consent for Professional Clone | Business plan for cloning API | 23 | ~$30 (estimate) |
| Hume | 15 s / not documented | Upload from a consenting speaker | Creator, $14/mo | 11 | $50 to $150 by plan |

Credit-plan rates equal the plan price divided by included characters. Resemble AI's pricing page lists no TTS rate; trackers report $0.0005 per second in mid-2026, converted here at roughly 1,000 characters per minute. Prices were checked September 20, 2026.

Speaker Similarity: What Public Data Shows

Hume released its Voice Replication Leaderboard on September 10, 2026. It evaluated 11 models against 25 reference voices using 7 prompts. Three blind raters graded each clip from 1 to 5 on how closely it resembled the reference.

Among the vendors covered here, Fish Audio s2-pro came out on top at 4.03. Cartesia sonic-3.5 scored 3.70, ElevenLabs Multilingual v2 scored 3.68, Cartesia sonic-3.6-beta scored 3.63, and Inworld TTS-2 scored 3.62. ElevenLabs Eleven v3 finished last among the 11 models at 2.91.

The board also illustrates why a single metric can mislead. Cartesia sonic-3.6-beta led naturalness at 4.36 yet placed only 8th on identity, while Inworld TTS-2 led audio quality at 4.61. Full per-category results are available on the Hugging Face leaderboard.

Provider Breakdown

ElevenLabs offers Instant Voice Cloning (IVC) and Professional Voice Cloning (PVC). IVC documentation recommends 1 to 2 minutes of clean audio; PVC requires at least 30 minutes—ideally 2 to 3 hours—on the Creator plan or above. It also has the strictest gate tested: the voice owner reads on-screen text aloud via Voice Captcha. API rates are $0.10 per 1K characters on Eleven v3 and Multilingual v2; Flash, Turbo, and v3 Conversational cost $0.05. Eleven v3 supports 70+ languages.

Cartesia clones from 10 seconds. Sonic 3.6 and newer can use up to 60 seconds to preserve accents better. Pro Voice Clones train on 30+ minutes and start on the $49 Startup plan. Sonic bills 1 credit per character, with plans from $5 for 100K credits to $299 for 8M. Sonic lists 44 languages.

Inworld instant clones work from 3 seconds, and samples up to 30 seconds improve similarity. Cloning is free. Realtime TTS-2 lists $25 per 1M characters on demand, dropping to $15 at $300 a month and $12.50 at $1,500; TTS-2 Flash starts at $15 and falls to $7. Professional cloning is in beta, requires 10 minutes of audio, and supports English only. Inworld supports 200+ languages and locales, 15 of them in its top quality tier.

Gradium, founded by Kyutai co-founders, clones from 10 seconds. The free tier includes 5 clones for non-commercial use. Paid plans start at $13 for 225K credits, billed at 1 credit per character. Pro Voice Clone requires a 30-minute minimum and starts on the $340 M plan. Language coverage is narrow: English, French, German, Spanish, and Portuguese.

Fish Audio bills its API at $15 per 1M UTF-8 bytes. English runs roughly 1 byte per character; Chinese, Japanese, and Korean run about 3, nearly tripling the effective cost. S2.1 Pro covers 83 languages. Instant clones work from about 10 seconds; professional clones take 10 to 180 minutes and require live ownership verification. Commercial use starts on the $15 Plus plan and covers verified voices you own.

Resemble AI Rapid Clone needs 10 seconds and completes in under a minute. Professional Clone requires 10 to 25+ minutes and about 40 minutes of training, with explicit, verifiable consent from the voice talent. PerTh watermarking is applied on every output. Chatterbox Multilingual covers 23 languages. The catch: Resemble now leads with deepfake detection, and its Voice Cloning API requires a Business plan or higher. Its pricing page no longer lists TTS rates.

Hume Octave clones from as little as 15 seconds, recorded live or uploaded from a consenting speaker. Octave 2 covers 11 languages. Commercial use starts on Creator at $14 a month; Free and Starter are non-commercial. Hume's pricing page lists API access to voice cloning only on Enterprise; other tiers create clones within the platform. Extra characters cost $0.15 per 1K on Creator, down to $0.05 on Business.

Which API Fits Which Job

• Budget voice agents at scale: Inworld or Fish Audio
• Low latency with broad language coverage: Cartesia
• Brand voices with strict consent: ElevenLabs PVC
• European languages with a free test tier: Gradium
• Cloning plus watermarking and deepfake detection: Resemble AI
• Emotion-directed delivery: Hume

Key Takeaways

ElevenLabs remains the category default, yet its models trail on Hume's new same-speaker leaderboard. Only ElevenLabs, Fish Audio, and Resemble AI document technical consent checks—and only for pro clones. Inworld and Fish Audio list $25 or less per 1M characters, while ElevenLabs v3 lists $100. Hume needs 15 seconds of audio, so a 10-second clip falls short. Language support ranges from 5 (Gradium) to 200+ languages and locales (Inworld).

FAQ

What is the best voice cloning API in 2026? No vendor wins on every axis. On Hume's September 2026 board, Fish Audio led the vendors covered here on same-speaker similarity. ElevenLabs offers the strongest consent gate for professional clones.

How much audio does voice cloning need? Instant clones need 3 to 30 seconds on most platforms. Professional clones need 10 to 30 minutes minimum, and 2 hours is often recommended.

Which voice cloning APIs verify consent? ElevenLabs, Fish Audio, and Resemble AI document technical checks for professional clones; the rest rely on attestation and terms of service.

What is the cheapest voice cloning API per 1M characters? Among self-serve list prices, Inworld TTS-2 Flash falls to $7 on higher plans. Fish Audio charges a flat $15 per 1M UTF-8 bytes for S2.1 Pro.

Meta description: We tested 7 voice cloning APIs with the same 10-second clip, comparing speaker similarity, consent checks, language support, and price per 1M characters.

Tags: voice cloning, ElevenLabs, text-to-speech, AI APIs, speech synthesis

Featured image: Abstract technology style—stylized soundwave forms splitting into parallel streams, cool blue and violet gradient, no people, logos, or text.