> Grok 4.3 is a closed AI model from xAI, released 17 Apr 2026. Index score 151 (GPT-4 = 100), rank 56 of 229 ranked models.

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# Grok 4.3

xAI

Released 17 Apr 2026

Closed

Flagship

[Compare](https://themodelindex.org/compare/grok-4-3-vs-kimi-k2-6/) [Announcement](https://docs.x.ai/developers/models/grok-4.3)

151140–163

Index score

#56 of 229 models

2/ 8

Core tests taken

2 of 6 areas · plus 8 anchor tests

−19

Versus the frontier at release

best then: GPT-5.4

–

Price per million tokens

no public API price found

–

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_

GPT-5 reached this score 8 months earlier.

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

Show 8 anchor tests

Reasoning & knowledge

evidence

GPQA Diamond

89%

Humanity's Last Exam

no result

Maths

evidence

FrontierMath T1-3

43%

Coding

evidence

SWE-bench Verified

no result

Terminal-Bench

no result

Agents

evidence

APEX-Agents

no result

Novel problems

no evidence yet

ARC-AGI-2

no result

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

#56

of 219 · 151

LMArena · Creative writing

creative writing

#72

of 386 · 1422

LMArena · Text

overall chat quality, judged by people

#84

of 388 · 1441

LMArena · Coding

coding questions in chat

#88

of 383 · 1488

Epoch Capabilities Index

overall capability from many benchmarks

#55

of 239 · 149.2

LMArena · Maths

maths questions in chat

#112

of 373 · 1419

LMArena · Vision

understanding images

#49

of 149 · 1244

LMArena · Search

answering with web search

#23

of 34 · 1165

LMArena · WebDev

building web apps and front ends

#93

of 123 · 1357

LiveBench · Overall

overall, with fresh questions to limit contamination

#58

of 58 · 62.3

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

1st

answering with web search

LMArena · Search

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

Grok

app · subscription

↗

xAI API

API

↗

#### API providers · 1 · per million tokens, in / out

x

xAI

$2.5 / $5.0

cheapest

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 Apr 2026

Announcement

[docs.x.ai ↗](https://docs.x.ai/developers/models/grok-4.3)

Release entry

Grok 4.3 (beta; API/GA 04-30)

Scored as

Grok 4.3 Beta

Artificial Analysis index

–

Output speed

–

Hugging Face

closed weights

## xAI releases · around this one

Grok 4.1 Fast

Closed

19 NOV 2025

Grok 4.20

Closed

17 FEB 2026

index 158

Grok 4.3

Closed

17 APR 2026

index 151

Grok Build 0.1

Closed

20 MAY 2026

Grok 4.5

Closed

8 JUL 2026

index 163

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Source: https://themodelindex.org/models/grok-4-3/ · The Model Index · data as of 2026-10-01