> Claude Sonnet 4.6 is a closed AI model from Anthropic, released 17 Feb 2026. Index score 160 (GPT-4 = 100), rank 40 of 229 ranked models. API price $3.0 in / $15 out per million tokens, 1M context.

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# Claude Sonnet 4.6

Anthropic

Released 17 Feb 2026

Closed

Flagship

Date verified

[Compare](https://themodelindex.org/compare/claude-sonnet-4-6-vs-kimi-k2-5/) [Announcement](https://www.anthropic.com/news/claude-sonnet-4-6)

160149–171

Index score

#40 of 229 models

5/ 8

Core tests taken

4 of 6 areas · plus 17 anchor tests

−10

Versus the frontier at release

best then: GPT-5.3-Codex

Replaced by [Claude Sonnet 5](https://themodelindex.org/models/claude-sonnet-5/)

$3.0/ $15

Price per million tokens

input / output, list price

1M

Context window

tokens it reads at once

## Where it sits · on the frontier

_Chart: Model Index score of every scored model since late 2022, with the best closed and best open model over time_

Gemini 3 Pro reached this score 3 months earlier.

## Test results · by area · tick = best by any model

Show 15 anchor tests

Reasoning & knowledge

evidence

GPQA Diamond

87%

Humanity's Last Exam

no result

Maths

evidence

FrontierMath T1-3

no result

Coding

evidence

SWE-bench Verified

75%

Terminal-Bench

53%

Agents

evidence

APEX-Agents

43%

Novel problems

evidence

ARC-AGI-2

60%

Long tasks

no evidence yet

METR time horizon

no result

Independent results from the Epoch AI benchmarking hub, best reasoning setting. The core tests are shown here; anchor tests also inform the score and can be shown above.

## What others say · rank on each leaderboard

The Model Index

independent tests, our method

#40

of 219 · 160

Epoch Capabilities Index

overall capability from many benchmarks

#39

of 239 · 152.3

LiveBench · Overall

overall, with fresh questions to limit contamination

#42

of 58 · 73

Further left is better. Leaderboards measure different things: LMArena is people voting blind between two answers, the others are test scores. Click any row for the source.

## Best at · top three among current models

2nd

SWE-bench Verified

Epoch AI · independent

Where this model places in the top three of today's models, on category leaderboards and on our core tests.

## Where to use it · prices checked 1 Oct 2026

#### From the lab

Claude

app · subscription

↗

Claude API

API

↗

#### API providers · 5 · per million tokens, in / out

C

Claude Platform on AWS

$3.0 / $15

cheapest

A

Azure

$3.0 / $15

↗

A

Anthropic

$3.0 / $15

↗

A

Amazon Bedrock

$3.3 / $16.5

↗

G

Google

$3.3 / $16.5

↗

Provider prices come from OpenRouter's live listing; going direct to a provider can differ. Subscriptions are the lab's own apps.

## Facts and sources

Released

17 Feb 2026

Announcement

[anthropic.com ↗](https://www.anthropic.com/news/claude-sonnet-4-6)

Release entry

Claude Sonnet 4.6

Scored as

Claude Sonnet 4.6

Artificial Analysis index

–

Output speed

–

Hugging Face

closed weights

## Anthropic releases · around this one

Claude Opus 4.5

Closed

24 NOV 2025

index 153

Claude Opus 4.6

Closed

5 FEB 2026

index 167

Claude Sonnet 4.6

Closed

17 FEB 2026

index 160

Claude Mythos Preview

Closed

7 APR 2026

Claude Opus 4.7

Closed

16 APR 2026

index 169

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Source: https://themodelindex.org/models/claude-sonnet-4-6/ · The Model Index · data as of 2026-10-01