Grok 4.6 Is Live: Intelligence Index 61, Level With GPT-5.6

Key Takeaways

New flagship, listed same week: Grok 4.6 shipped on August 7, 2026 and is live on APIYI as grok-4.6
Intelligence Index 61: the Artificial Analysis Intelligence Index (High tier) rises from Grok 4.5’s 56 to 61, matching GPT-5.6 Sol Max
Gains from post-training, not scale: it reuses Grok 4.5’s 1.5T-parameter V9 foundation, with the entire delta going into supervised fine-tuning (SFT) and reinforcement learning (RL)
Stronger self-verification on long tasks: xAI reports markedly better self-testing and verification on long-running work, and faster first-draft scaffolding on interactive projects
Official list price, then 20% off: $2.00 / $6.00 per million tokens matches xAI’s own pricing; the GrokOfficial group runs at a 0.8x multiplier, and stacking a 10%–20% top-up bonus brings input down to $1.33 and output to $4.00

Background

After Grok 4.5 landed on July 8, 2026, Elon Musk previewed an unusually tight cadence: 4.6 in about two weeks, 4.7 a month after that. On August 7, SpaceXAI shipped Grok 4.6 — one month after its predecessor. The engineering choice here is worth calling out on its own: Grok 4.6 did not change the base model. It reuses Grok 4.5’s 1.5T-parameter V9 foundation and puts the entire increment into supervised fine-tuning and reinforcement learning. In other words, this is a post-training release rather than a scaling release — and because neither training nor inference cost moved, the list price didn’t either. For anyone already running the model, the practical read is simple: same price, same speed, same token efficiency, five more points of intelligence index. If grok-4.5 is already in production, the marginal cost of switching is close to zero.

Deep Dive

Benchmarks (data retrieved 2026/8/13)

Benchmark / metric	Grok 4.6	Grok 4.5	Reference
Artificial Analysis Intelligence Index (High)	61	56	Level with GPT-5.6 Sol Max
GDPval-AA v2 (sustained knowledge work)	Top tier	Elo 1543	—
AA-Briefcase	Top tier	—	—
Harvey LAB (legal agent)	Top tier	1st	—
Parameter count	1.5T (V9 foundation, same as 4.5)	1.5T	—

Sources: the SpaceXAI announcement x.ai/news/grok-4-6, artificialanalysis.ai, and coverage from TradingKey and kie.ai; data retrieved August 13, 2026. xAI has not published per-benchmark SWE-Bench Pro / Terminal Bench figures for 4.6, so the table only lists what is public.

Core Capabilities

Long-task self-verification

xAI highlights stronger self-testing and verification on long-running agent tasks, so multi-step work drifts less — a fit for codebase collaboration and idea-to-app workflows

500K context

A 500K-token context window with text and image input; requests above 200K are billed at the second, higher-context tier

Cost and speed unchanged

Same foundation means Grok 4.5’s token efficiency and output speed carry over, at an unchanged list price

Native in Codex

Grok supports /v1/responses natively, so it runs inside OpenAI Codex over the native responses protocol

Specifications

Item	Value
Model name	`grok-4.6`
Context window	500K tokens
Input modalities	Text, image
Endpoints	`/v1/chat/completions`, `/v1/responses`
Billing	Tiered, with the break at 200K tokens

Putting It to Work

Where it fits

Long-horizon coding agents: self-verification is the headline upgrade this generation, which cuts rework on long chains
Knowledge work and professional agents: top-tier on GDPval-AA v2, AA-Briefcase, and Harvey LAB
Existing grok-4.5 workloads: same price, same speed — swapping the model name is a straight gain
Codex / IDE integration: native responses protocol, with tool calls and reasoning items intact

Code sample

import openai

client = openai.OpenAI(
    api_key="sk-your-apiyi-key",
    base_url="https://api.apiyi.com/v1"
)

response = client.chat.completions.create(
    model="grok-4.6",
    messages=[
        {"role": "user", "content": "Refactor this code and explain what you changed"}
    ]
)
print(response.choices[0].message.content)

It is OpenAI-compatible, so existing code only needs the model value changed to grok-4.6. Integration details, the four server-side tools, and parameter caveats are the same as the rest of the Grok 4.x line — see the Grok overview.

Grok 4.x chat models run internal reasoning by default, and reasoning tokens are billed as output. For cost-sensitive short-answer traffic, see the model-selection guidance in Chat and Reasoning.

Pricing and Availability

List price

Identical to xAI’s own pricing, billed in tiers:

Context tier	Input	Output	Cached input
0 – 200K tokens	$2.00 / 1M	$6.00 / 1M	$0.50 / 1M
200K – 512K tokens	$4.00 / 1M	$12.00 / 1M	$1.00 / 1M

Group discount, and what stacks

The GrokOfficial direct-relay group runs at a 0.8x multiplier — 20% off the default group’s price — with identical model behavior and call syntax. Select the group when creating a token; no code changes required. The discount stacks with top-up bonuses. Taking the first tier as the example:

Basis	Input / 1M tokens	Output / 1M tokens
xAI official	$2.00	$6.00
APIYI list	$2.00 (same as official)	$6.00 (same as official)
`GrokOfficial` at 0.8x	$1.60	$4.80
0.8x + 10% top-up bonus	$1.45	$4.36
0.8x + 20% top-up bonus	$1.33	$4.00

Stacking top-up promotions

Tiered top-up bonuses run 10%–20% (calculated per single top-up), and stack with the group discount to push the effective rate lower still — see Top-up promotions.

Verdict

Grok 4.6 is a capability upgrade with no price attached: the foundation didn’t move, the price didn’t move, speed and token efficiency didn’t move — and the intelligence index went from 56 to 61, level with GPT-5.6 Sol Max. That shape of release is about as friendly to existing users as it gets: changing grok-4.5 to grok-4.6 is pure upside, with no cost model to redo. If your workload is long-horizon coding agents, tool-heavy automation pipelines, or professional agents in legal and consulting, make grok-4.6 the default. For extremely cost-sensitive traffic on simple tasks, grok-4.3 (1M context, $1.25/$2.50) is still cheaper. To get the lowest effective rate, run on the GrokOfficial group and stack a top-up bonus.

Sources: the SpaceXAI announcement x.ai/news/grok-4-6, the xAI developer docs docs.x.ai/docs/models, Artificial Analysis, and TradingKey; data retrieved August 13, 2026. The model is live on APIYI — grab a key and start calling.

Changelog

AI Radar

Grok 4.6 Is Live: Intelligence Index 61, Level With GPT-5.6

Key Takeaways

Background

Deep Dive

Benchmarks (data retrieved 2026/8/13)

Core Capabilities

Long-task self-verification

500K context

Cost and speed unchanged

Native in Codex

Specifications

Putting It to Work

Where it fits

Code sample

Pricing and Availability

List price

Group discount, and what stacks

Stacking top-up promotions

Verdict

​Key Takeaways

​Background

​Deep Dive

​Benchmarks (data retrieved 2026/8/13)

​Core Capabilities

Long-task self-verification

500K context

Cost and speed unchanged

Native in Codex

​Specifications

​Putting It to Work

​Where it fits

​Code sample

​Pricing and Availability

​List price

​Group discount, and what stacks

​Stacking top-up promotions

​Verdict

Key Takeaways

Background

Deep Dive

Benchmarks (data retrieved 2026/8/13)

Core Capabilities

Specifications

Putting It to Work

Where it fits

Code sample

Pricing and Availability

List price

Group discount, and what stacks

Stacking top-up promotions

Verdict