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xAIGrok 4 familyCurrentReasoning modelReleased Apr 2026

Grok 4.3

Cost-efficient 1M-context Grok for long documents and high-volume agents.

Model idgrok-4.3

Price$1.25 in, $2.50 out per 1M tokens

Checked29 September 2026

No published training cutoff

At least1,863events since its release in April 2026

83 historic, 426 major. 197 days of news.

xAI doesn’t publish a training cutoff, so we count from its release date. The real gap is larger.

Five things it has never heard of

How to call it

4 ways to use Grok 4.3, with the model id each provider expects.

Providers, model ids, endpoints and docs for Grok 4.3
ProviderModel idEndpointDocs
xAI API grok-4.3 https://api.x.ai/v1/chat/completions docs.x.ai
AWS Bedrock xai.grok-4.3 docs.aws.amazon.com
OpenRouter x-ai/grok-4.3 openrouter.ai
Web app grok.com

Pricing

Prices for Grok 4.3
Input$1.25 per 1M tokens
Cached input$0.20 per 1M tokens
Output$2.50 per 1M tokens
Input, prompts over 200K tokens$2.50 per 1M tokens
Output, prompts over 200K tokens$5 per 1M tokens

As published: “per 1M tokens (USD); Batch API 20% off”.

Source: docs.x.ai, checked 29 September 2026.

Specs

Input
Text and images
Output
Text
Context window
1,000,000 tokens
Max output
Not published
Open weights
No
Licence
Proprietary
Training cutoff
Not published
Released
April 2026
Status
Current
Type
Reasoning model

What stands out

What its maker marketed at launch, and what people found later, each with its source.

  • 1M context at budget price

    1M-token context window at $1.25/$2.50, cheaper than the 500K-context Grok 4.5-4.7 line.

    Source: docs.x.ai

  • Reasoning effort incl. none

    Reasoning effort none / low / medium / high / xhigh, default low - usable as a fast non-reasoning model.

    Source: docs.x.ai

Notes

Alias grok-4.3-latest. Cheaper long-context option still offered alongside Grok 4.7.

curl https://api.x.ai/v1/chat/completions -H "Authorization: Bearer $XAI_API_KEY" -H "Content-Type: application/json" \
 -d '{"model":"grok-4.3","messages":[{"role":"user","content":"Hello"}]}'

Sources: https://docs.x.ai/docs/models , https://docs.x.ai/docs/models/grok-4.3

Not yet checked against an official source: Release month inferred from OpenRouter listing date (2026-04-30); exact date not verified.