xAI

Grok 4.3

Grok 4.3 is xAI’s frontier language model, designed for developers building reasoning-heavy applications, agentic workflows, and long-context systems. It is a balanced choice for general-purpose tasks where tool integration and structured outputs are required.

Modalities

Text+Image → Text

Input

$1.688 /1M

Output

$3.375 /1M

Cached input

$0.1688 /1M90% off

Context

Speed

medium

Performance

Live production data from real requests on Kyma — not synthetic benchmarks.

Rank

#24

of 87 active models

Tokens served

3.6M

all-time

Success rate

100%

last 7 days

Median throughput112 tok/s

Total requests346

Platform share0.2%

Tokens · last 15 daysJul 19 → Aug 2

Top apps using this model

1OpenCode1.1M tok

2Node.js App32.0K tok

Public apps sending the most traffic to this model — a signal of what real workloads it fits.

Pricing

Pay per token. Cached input is billed at 10% of the input rate.

$1.688 /1M input$3.375 /1M output

Hobby10 req/day · 2K in / 500 out

~$1.52/mo

Production1,000 req/day · 2K in / 500 out

~$152/mo

Scale20,000 req/day · 2K in / 500 out

~$3,038/mo

+ Estimate your workload

Requests / day1,000

Input tokens / request2,000

Output tokens / request500

Cache hit rate30%

Estimated monthly cost

$125

$4.15 / day on Grok 4.3

Same workload on:

Grok 4.20 Multi-Agent$152+22%

Grok 4.20$152+22%

Estimates use list pricing with cached input billed at the 90%-discount rate. Actual bills depend on real token counts — every response includes its exact cost.

When to use Grok 4.3

Updated 2026-07-31

Where this model earns its cost — and where it doesn't.

Grok 4.3 is a text-only language model from xAI that supports a 1,000,000-token context window and a maximum output of 32,768 tokens. It is optimized for reasoning, tool use, and structured output generation, making it suitable for chat interfaces, code generation, and autonomous agent pipelines.

On Kyma, the model runs through an OpenAI-compatible endpoint with automatic request failover and exact cost reporting in the usage.cost field. Prompt caching is supported, reducing repeated prefix costs to 10% of the standard input rate. Live telemetry shows a 100% success rate across served requests with a median throughput of 47 tokens per second.

The model does not support vision or multimodal inputs, and its output length is capped at 32,768 tokens. It operates at a medium speed tier, which may introduce latency in high-throughput streaming applications compared to lighter models.

Agentic Workflow Orchestration

Leverages built-in tool calling and reasoning to coordinate multi-step autonomous tasks.

Long Context Document Analysis

Processes up to one million tokens to summarize or query extensive text corpora.

Code Generation and Review

Generates and refines code snippets while maintaining structured output formats.

General Purpose Chat Interfaces

Handles conversational turn-taking with reliable reasoning and balanced latency.

Not ideal for: It is not suitable for applications requiring image or video understanding, or for workloads that demand high-throughput streaming speeds.

How it compares

Against the peers people actually weigh it against.

Spec	Grok 4.3	Grok 4.20 Multi-Agent	Grok 4.20
Input /1M	$1.688	$1.688	$1.688
Output /1M	$3.375	$3.375	$3.375
Context	1M	2M	2M
Tools	Yes	No	Yes
Reasoning	Yes	Yes	Yes
Speed	medium	slow	medium

Quick start

Up and running in under two minutes.

1
Create an API key
Sign up and grab a key from the dashboard — $0.50 free credit, no card required.
Get API key →

Make your first request

Drop in your key and send a chat completion — fully OpenAI-compatible.

curl https://kymaapi.com/v1/chat/completions \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "grok-4.3",
    "messages": [
      {"role": "user", "content": "Explain prompt caching in one paragraph."}
    ]
  }'

Stream responses

Add "stream": true to receive tokens as they arrive.

curl https://kymaapi.com/v1/chat/completions \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "grok-4.3",
    "stream": true,
    "messages": [{"role": "user", "content": "Hello!"}]
  }'

FAQ

Common questions about this model.

What is the context window of Grok 4.3?

Grok 4.3 has a 1M-token context window — roughly 1471 pages of text in a single request.

How much does the Grok 4.3 API cost?

$1.688 per 1M input tokens and $3.375 per 1M output tokens, with cached input at $0.1688/1M — a 90% discount on repeated prompt prefixes. No subscription; you pay only for what you use.

Does Grok 4.3 support function calling?

Yes — Grok 4.3 supports tool/function calling and structured outputs (JSON mode), so it works with agent frameworks out of the box.

How do I use Grok 4.3?

Kyma is OpenAI-compatible: point your SDK's base URL at https://kymaapi.com/v1, use your Kyma API key, and set the model to grok-4.3. Signing up is free and includes $0.50 of credit — no card required.

Does Grok 4.3 support image inputs?

No, the model accepts text-only inputs and does not support vision or multimodal processing.

How does prompt caching work on Kyma for this model?

Repeated prompt prefixes are billed at 10% of the standard input rate, automatically applied when caching is enabled.

What happens if the serving path experiences degradation?

Kyma automatically reroutes the request to a healthy serving path, ensuring consistent availability without manual intervention.

Start with $0.50 free credit — no card required.Create account →

More models by xAI

Model	Context	Input	Output
Grok 4.5	500K	$2.70	$8.10
Grok Build	256K	$1.389	$2.777
Grok 4.20	2M	$1.688	$3.375
Grok 4.20 Multi-Agent	2M	$1.688	$3.375