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CartesiaAudio modelActive

Sonic 3.6

PopularityRank 279 of 875

39out of 100same as last month

Summary

Sonic 3.6 is Cartesia’s fast, natural-sounding text-to-speech model with support for 44 languages. It follows the transcript closely, speaks confirmation codes and difficult heteronyms without preprocessing, and adapts pauses and pacing to context. The documented language expansion also includes Latin-script Hindi, Odia, and Urdu.

Cartesia uses sonic-3.6 as an alias for the latest stable snapshot, while sonic-3.6-2026-08-27 stays on that dated version. The two identifiers therefore differ in reproducibility, not in the documented model family.

All benchmark results

Every published result with its source, test setup and comparison models.

Show all 147 published benchmark results

Page 1 of 13

Measurements without matching peer values

These measurements have no matching peer values under the same test conditions. Their original values and sources remain available here.

Coval pooled corpus-level synthesized-speech word error rate (TTS WER) (Show measurement, test conditions, and source)
Source value
1.4981466606730975
Score
1.4981466606730975
Metric
Pooled corpus-level synthesized-speech word error rate, Coval pooled_value
Unit
%
Benchmark version
Coval rolling 30-day window, re-measured daily; route last measured 2026-10-16
Category
audio
Direction
Lower is better
Sample
2100
Source type
official-leaderboard
Evaluator
Coval
Status
superseded
Retrieved at
2026-10-16
Methodology
Official benchmark leaderboard. Coval endpoint key cartesia/sonic-3.6, exact Cartesia API model ID sonic-3.6, hosted by Cartesia. This is a model-scoped synthesized-speech WER observation; the public route does not identify the tested voice. It is not STT WER. Rolling 30-day window, re-measured daily.
Context
This is Coval's pooled corpus-level synthesized-speech WER for the exact Sonic 3.6 endpoint, not the separate per-clip mean_value or a rounded leaderboard headline. Pooled WER and mean per-clip WER are different aggregations and should not be compared as the same score. The WER row's sample_count is used, not another metric's count or a roster total. It measures output intelligibility, not STT accuracy. The tested voice is not identified by the public route, so this is not a voice-specific result. Results are from Coval's hosted Cartesia endpoint, not local or native performance.
Source Coval
Blind native-speaker preference share, English (US) vs Eleven v3 (Show measurement, test conditions, and source)
Source value
92
Score
92
Metric
Share of valid blind pairwise votes preferring Cartesia Sonic 3.6 for English (US) over Eleven v3
Unit
%
Benchmark version
Cartesia internal blind native-speaker preference report, article published 2026-08-27
Category
audio
Direction
Higher is better
Source type
vendor-reported
Evaluator
Cartesia Sonic 3.6 launch report
Status
active
Retrieved at
2026-10-17
Methodology
Vendor-reported result. Cartesia reports a blind pairwise preference test with native-speaker panels. For this exact locale row, Sonic 3.6 was compared with the named competitor using a comparable voice; the displayed share is the model's wins divided by total valid votes.
Context
Vendor-run preference study. Cartesia does not publish per-locale vote counts, confidence intervals, or an immutable serving revision; percentages should not be treated as a cross-locale ranking.
Source Cartesia Sonic 3.6 launch report
Blind native-speaker preference share, English (UK) vs Eleven v3 (Show measurement, test conditions, and source)
Source value
72
Score
72
Metric
Share of valid blind pairwise votes preferring Cartesia Sonic 3.6 for English (UK) over Eleven v3
Unit
%
Benchmark version
Cartesia internal blind native-speaker preference report, article published 2026-08-27
Category
audio
Direction
Higher is better
Source type
vendor-reported
Evaluator
Cartesia Sonic 3.6 launch report
Status
active
Retrieved at
2026-10-17
Methodology
Vendor-reported result. Cartesia reports a blind pairwise preference test with native-speaker panels. For this exact locale row, Sonic 3.6 was compared with the named competitor using a comparable voice; the displayed share is the model's wins divided by total valid votes.
Context
Vendor-run preference study. Cartesia does not publish per-locale vote counts, confidence intervals, or an immutable serving revision; percentages should not be treated as a cross-locale ranking.
Source Cartesia Sonic 3.6 launch report
Blind native-speaker preference share, English (Australia) vs Eleven v3 (Show measurement, test conditions, and source)
Source value
77
Score
77
Metric
Share of valid blind pairwise votes preferring Cartesia Sonic 3.6 for English (Australia) over Eleven v3
Unit
%
Benchmark version
Cartesia internal blind native-speaker preference report, article published 2026-08-27
Category
audio
Direction
Higher is better
Source type
vendor-reported
Evaluator
Cartesia Sonic 3.6 launch report
Status
active
Retrieved at
2026-10-17
Methodology
Vendor-reported result. Cartesia reports a blind pairwise preference test with native-speaker panels. For this exact locale row, Sonic 3.6 was compared with the named competitor using a comparable voice; the displayed share is the model's wins divided by total valid votes.
Context
Vendor-run preference study. Cartesia does not publish per-locale vote counts, confidence intervals, or an immutable serving revision; percentages should not be treated as a cross-locale ranking.
Source Cartesia Sonic 3.6 launch report
Blind native-speaker preference share, Spanish (Mexico) vs Eleven v3 (Show measurement, test conditions, and source)
Source value
70
Score
70
Metric
Share of valid blind pairwise votes preferring Cartesia Sonic 3.6 for Spanish (Mexico) over Eleven v3
Unit
%
Benchmark version
Cartesia internal blind native-speaker preference report, article published 2026-08-27
Category
audio
Direction
Higher is better
Source type
vendor-reported
Evaluator
Cartesia Sonic 3.6 launch report
Status
active
Retrieved at
2026-10-17
Methodology
Vendor-reported result. Cartesia reports a blind pairwise preference test with native-speaker panels. For this exact locale row, Sonic 3.6 was compared with the named competitor using a comparable voice; the displayed share is the model's wins divided by total valid votes.
Context
Vendor-run preference study. Cartesia does not publish per-locale vote counts, confidence intervals, or an immutable serving revision; percentages should not be treated as a cross-locale ranking.
Source Cartesia Sonic 3.6 launch report
Blind native-speaker preference share, Spanish (Spain) vs Eleven v3 (Show measurement, test conditions, and source)
Source value
91
Score
91
Metric
Share of valid blind pairwise votes preferring Cartesia Sonic 3.6 for Spanish (Spain) over Eleven v3
Unit
%
Benchmark version
Cartesia internal blind native-speaker preference report, article published 2026-08-27
Category
audio
Direction
Higher is better
Source type
vendor-reported
Evaluator
Cartesia Sonic 3.6 launch report
Status
active
Retrieved at
2026-10-17
Methodology
Vendor-reported result. Cartesia reports a blind pairwise preference test with native-speaker panels. For this exact locale row, Sonic 3.6 was compared with the named competitor using a comparable voice; the displayed share is the model's wins divided by total valid votes.
Context
Vendor-run preference study. Cartesia does not publish per-locale vote counts, confidence intervals, or an immutable serving revision; percentages should not be treated as a cross-locale ranking.
Source Cartesia Sonic 3.6 launch report
Blind native-speaker preference share, Portuguese (Brazil) vs Eleven v3 (Show measurement, test conditions, and source)
Source value
67
Score
67
Metric
Share of valid blind pairwise votes preferring Cartesia Sonic 3.6 for Portuguese (Brazil) over Eleven v3
Unit
%
Benchmark version
Cartesia internal blind native-speaker preference report, article published 2026-08-27
Category
audio
Direction
Higher is better
Source type
vendor-reported
Evaluator
Cartesia Sonic 3.6 launch report
Status
active
Retrieved at
2026-10-17
Methodology
Vendor-reported result. Cartesia reports a blind pairwise preference test with native-speaker panels. For this exact locale row, Sonic 3.6 was compared with the named competitor using a comparable voice; the displayed share is the model's wins divided by total valid votes.
Context
Vendor-run preference study. Cartesia does not publish per-locale vote counts, confidence intervals, or an immutable serving revision; percentages should not be treated as a cross-locale ranking.
Source Cartesia Sonic 3.6 launch report
Blind native-speaker preference share, French vs Eleven v3 (Show measurement, test conditions, and source)
Source value
86
Score
86
Metric
Share of valid blind pairwise votes preferring Cartesia Sonic 3.6 for French over Eleven v3
Unit
%
Benchmark version
Cartesia internal blind native-speaker preference report, article published 2026-08-27
Category
audio
Direction
Higher is better
Source type
vendor-reported
Evaluator
Cartesia Sonic 3.6 launch report
Status
active
Retrieved at
2026-10-17
Methodology
Vendor-reported result. Cartesia reports a blind pairwise preference test with native-speaker panels. For this exact locale row, Sonic 3.6 was compared with the named competitor using a comparable voice; the displayed share is the model's wins divided by total valid votes.
Context
Vendor-run preference study. Cartesia does not publish per-locale vote counts, confidence intervals, or an immutable serving revision; percentages should not be treated as a cross-locale ranking.
Source Cartesia Sonic 3.6 launch report
Blind native-speaker preference share, Hindi vs Gemini 3.1 (Show measurement, test conditions, and source)
Source value
55
Score
55
Metric
Share of valid blind pairwise votes preferring Cartesia Sonic 3.6 for Hindi over Gemini 3.1
Unit
%
Benchmark version
Cartesia internal blind native-speaker preference report, article published 2026-08-27
Category
audio
Direction
Higher is better
Source type
vendor-reported
Evaluator
Cartesia Sonic 3.6 launch report
Status
active
Retrieved at
2026-10-17
Methodology
Vendor-reported result. Cartesia reports a blind pairwise preference test with native-speaker panels. For this exact locale row, Sonic 3.6 was compared with the named competitor using a comparable voice; the displayed share is the model's wins divided by total valid votes.
Context
Vendor-run preference study. Cartesia does not publish per-locale vote counts, confidence intervals, or an immutable serving revision; percentages should not be treated as a cross-locale ranking.
Source Cartesia Sonic 3.6 launch report
Gradium hard-case TTS overall sentence pass rate (Show measurement, test conditions, and source)
Source value
75.1
Score
75.1
Metric
All-criteria share of sentences where every element is pronounced correctly and completely; higher is better
Unit
%
Benchmark version
Gradium hard-case TTS set, generated 2026-08; source article 2026-08-31; default settings
Direction
Higher is better
Source type
vendor-reported
Evaluator
Gradium, Gradium TTS: you no longer have to choose between latency and accuracy
Status
active
Retrieved at
2026-10-17
Methodology
Vendor-reported result. Gradium hard-case TTS evaluation generated in August 2026 with default settings. The 500-sentence set has 100 sentences per language in English, German, French, Spanish, and Portuguese. Independent native-speaker raters heard randomized, loudness-normalized outputs. The all-criteria sentence pass rate is pooled across ten criteria and averaged across the five languages with equal language weights. Voice IDs and immutable API revisions are not published. Exact table model: Cartesia Sonic 3.6.
Context
Gradium is a competing TTS vendor and reports its own comparison; source type is vendor-reported, not an independent leaderboard. The four comparison models were selected by Gradium. The score is macro-weighted across languages and criteria, so no single pooled sentence denominator or confidence interval is asserted. Voice IDs and serving revisions are unspecified.
Source Gradium, Gradium TTS: you no longer have to choose between latency and accuracy
Cartesia-reported maximum blind head-to-head listener preference vs Sonic-3.5 across 15 locales (Show measurement, test conditions, and source)
Source value
93
Score
93
Metric
Maximum reported share of blind head-to-head tests preferring Sonic-3.6 over Sonic-3.5; source says “up to” across 15 locales
Unit
%
Category
audio
Direction
Higher is better
Source type
vendor-reported
Evaluator
Cartesia TTS Research, Introducing Sonic-3.6
Status
active
Retrieved at
2026-10-19
Methodology
Vendor-reported result. Cartesia's 2026-08-27 product-research post says listeners preferred Sonic-3.6 over Sonic-3.5 in up to 93% of blind head-to-head tests across fifteen locales. This is the publisher's maximum/ceiling claim, not a mean or overall 15-locale score.
Context
Vendor-reported, not an independent evaluation. The captured post does not identify which locale/test produced the “up to 93%” ceiling, preference-test N, confidence intervals, or full per-locale result table. The separate 92% US-English claim against Eleven v3 is already present in the baseline and is not added.
Source Cartesia TTS Research, Introducing Sonic-3.6
Cekura TTS hard-part accuracy: numbers and shorthand (Show measurement, test conditions, and source)
Source value
71
Score
71
Metric
Share of hard-part readings accepted for numbers and shorthand
Unit
%
Benchmark version
Cekura TTS Model Benchmarks; current page snapshot 2026-10-19; run date and serving revision not stated
Category
audio
Direction
Higher is better
Source type
official-leaderboard
Evaluator
Cekura Bench TTS Model Benchmarks
Status
active
Retrieved at
2026-10-19
Methodology
Official benchmark leaderboard. Evaluator-run TTS benchmark. Cekura says each model read the same 104 agent sentences three times from one US East cloud region, using one stock voice and its own streaming protocol. Non-streaming timing runs from sending the full text to first audible sound; streaming timing runs from the last word sent to first audible sound. Reading accuracy is estimated from Deepgram Nova-3 and OpenAI Whisper transcripts, counting accepted readings without human review. Naturalness uses UTMOS, an open model predicting a listening-test score. The captured rows do not state per-cell N, CI, exact run date, serving/API revision, or exact voice ID unless shown separately.
Context
Cekura discloses that it runs the benchmark itself and sells testing and monitoring tools in the same market. The results are evaluator-published and include voice, runtime, protocol, ASR, and UTMOS effects; they are not a human-only or isolated-model evaluation.
Source Cekura Bench TTS Model Benchmarks

Page 1 of 13

Popularity compared

How often the model is searched for, used and mentioned, compared with every model of its category.

Popularity index

0 to 100, higher is more popular

20 of 83 models

As of November 2026 · Source: gradually.ai popularity index

Over time

Weekly values from October 18, 2026 to November 5, 2026

Sonic 3.6Eleven v3GPT-Live-TranscribeScribe v2Maya 2 Native

All specifications

Architecture

Model class
Text-to-speech
Source: Model class

Input and output

Input
Text
Source: Input
Output
Audio
Source: Output

Watermarking and provenance

AI watermarking refers to invisible signals embedded in the output. Visible marks and provenance metadata are listed separately. Unknown means there is insufficient evidence for that particular field.

AI watermarking
Unknown
no source
Watermarking technique
Not known
no source

Licence and access

API

API model ID
sonic-3.6
Source: API model ID

Further details

Task
Speech generation
Source: Task
Supported details
44 languages and stable dated snapshots
Source: Supported details
Versions
sonic-3.6 tracks the current stable release; dated snapshots remain fixed
Source: Versions
Stable snapshot
sonic-3.6-2026-08-27
Source: Stable snapshot

Sources and data date

Show all 43 sources

Benchmark sources at a glance

Which independent evaluators tested this model. This is coverage, not a quality ranking.

No active result from the reviewed external evaluators can currently be attributed to this model. Other source evidence remains available below.

Without vendor claims and historical or disputed results; those stay labelled in the single values.

TypeEvidence and data date
Research statusResearch date October 15, 2026. 38 source URLs checked. This documents the inspected sources, not an exhaustive inventory of every publication.
Unresolved

exact-serving-snapshot-and-unpublished-method-details

Note

The captured external source reports a benchmark-specific model or hosted route but does not establish an immutable currently served checkpoint. Unpublished row-level denominators and confidence intervals remain unknown; sample counts were entered only for cells that state them.

Unresolved

vendor preference experiment N and per-locale breakdown

Note

Cartesia's post gives an “up to 93%” ceiling across 15 locales but not the locale producing it, denominator, confidence interval, or full results. The separate 92% US-English row in the baseline is not re-added.

Additional sourceCartesia model documentation (retrieved September 24, 2026) · Cartesia Sonic 3.6 documentation · Editorial description reviewed October 2, 2026
Additional sourceArtificial Analysis (retrieved October 15, 2026; October 16, 2026; October 19, 2026; November 3, 2026)
Additional sourceCoval (retrieved October 16, 2026; October 28, 2026; October 29, 2026; October 30, 2026; October 31, 2026; November 1, 2026; November 2, 2026; November 5, 2026; November 6, 2026)
Additional sourceCartesia Sonic 3.6 launch report (retrieved October 17, 2026; October 19, 2026; October 24, 2026)
Additional sourceGradium, Gradium TTS: you no longer have to choose between latency and accuracy (retrieved October 17, 2026)
Additional sourceSpeko TTS benchmark (retrieved October 18, 2026)
Additional sourceCekura Bench TTS Model Benchmarks (retrieved October 19, 2026; October 23, 2026)
Additional sourceSpeko Benchmarks, TTS benchmark dataset (retrieved October 18, 2026; October 20, 2026)
Additional sourceCoval Voice AI Benchmarks (retrieved October 23, 2026)
Additional sourceAskable Labs VOICE-H (retrieved October 24, 2026)
Additional sourceArtificial Analysis (retrieved October 28, 2026; October 29, 2026; October 30, 2026; November 3, 2026)12
Additional sourceDesignArena (retrieved October 28, 2026)
Additional sourceVoiceArena primary public leaderboard (retrieved October 28, 2026)
Additional sourceModel metadata (retrieved October 15, 2026; October 16, 2026) · Cartesia Sonic 3.6 latest model documentation · Editorial description reviewed October 2, 2026
Additional sourceModel metadata (retrieved October 16, 2026)12
Additional sourceModel metadata (retrieved October 18, 2026)
Additional sourceModel metadata (retrieved October 28, 2026)12345678910111213
Additional sourceModel metadata (retrieved November 5, 2026)123
Additional sourceModel metadata (retrieved November 6, 2026)123
Additional sourceOpenRouter: Popularity index (derived), CC BY 4.0
Additional sourceVercel AI Gateway: Popularity index (derived), CC BY 4.0
Additional sourceOllama: cumulative downloads for the popularity index
Additional sourceReplicate: cumulative runs for the popularity index
Additional sourceGoogle Trending Now: limited feed selection for Germany and the US
Additional sourceCreative Commons Attribution 4.0