Grok 4.6: Benchmarks, Pricing and What Changed (2026 Launch Guide)

xAI shipped Grok 4.6 on August 12, 2026, just 35 days after Grok 4.5. The underlying checkpoint is dated August 10, and the API model id is simply grok-4.6.

This is a developer-first release. xAI's announcement talks about Grok Build, Cursor and the API — grok.com and the consumer apps are not mentioned once. Here is what actually changed, what the benchmarks say, and where the numbers need reading carefully.

What are Grok 4.6's specifications?

xAI has published no architecture details — no parameter count, no mixture-of-experts disclosure, no training compute, and no system card. Claims circulating that 4.6 is the same base model with longer post-training are outside speculation, not vendor statements.

Two naming points worth clearing up

There is no "Grok 4.6 High" model. You will see that label on benchmark sites. It refers to the default reasoning_effort setting, not a separate SKU. There is one model id.

The new level is xhigh. Grok 4.5 silently downgraded that request to high; 4.6 actually honours it. Separately, the "faster version at double the price" is Priority Processing — a service_tier flag, not a different model.

What does Grok 4.6 cost?

Two things here deserve more attention than the headline "pricing unchanged".

The cached-input price rose 67%. That is the token class agent loops hit hardest — every turn re-sends the accumulated conversation. If you run long agentic sessions, this is the line item that moves.

Crossing 200K tokens doubles the rate on the entire request, not just the tokens above the threshold. A 210K-token prompt is billed at $4/$12 across all 210K. Watch this if you feed large repositories in.

The combined effect shows up in measured cost. Artificial Analysis puts the cost to complete its standard task set at $0.837 for Grok 4.6 against $0.360 for Grok 4.5 — a 2.32x increase generation over generation, driven by roughly 47% more output tokens plus the cache price rise. Per-token pricing held; cost per job did not.

How does Grok 4.6 perform on benchmarks?

Start with the number xAI led on: 61 on the Artificial Analysis Intelligence Index. AA independently measured 60.92, so the claim is clean — worth noting, because not every vendor's launch numbers survive contact with an independent evaluator.

That places it 4th:

The gap to GPT-5.6 Sol Max is 0.01 points — a tie in any practical sense. The gap to Claude Opus 5 is real.

The Terminal-Bench version trap

This is the single most important thing to get right about Grok 4.6's numbers, and most coverage this week will get it wrong.

26% and 88% are the same model on different benchmark versions. v3.0 is far harder. Any article placing those side by side is producing nonsense. On v3.0, GPT-5.6 Sol scores 34.6% and beats Grok; on v2.1 as measured by AA, Grok leads.

Note also the 10-point spread between AA and Vals on the same version — a useful reminder that a benchmark score measures a model plus a harness. And the official tbench.ai board should not be cited as current: it has been stale since July 11 and contains neither Grok 4.6, Claude Opus 5, Gemini 3.6, Kimi K3 nor Muse Spark 1.2.

Where Grok 4.6 genuinely wins

• SWE-bench (Vals): 95.60%, up about 9 points on Grok 4.5. This is the strongest verified result in the release.
• Turn efficiency. AA measured roughly 53 turns and 0.5B input tokens to complete its agent task set, against Claude Opus 5's ~103 turns and 2.0B tokens. On long-horizon work that efficiency translates into real money — roughly 4x cheaper than Opus 5 on AA-Briefcase.
• WebDev Arena: 5th.
• LiveCodeBench: 88.2%, top-4.

Where it does not

• Agentic coding regressed. LiveBench's early listing puts Grok 4.6's agentic coding at 54.2 against Grok 4.5's 56.5. Non-agentic coding improved by over 6 points, so this is a specific regression — and it sits awkwardly beside xAI's own framing about a focus on long-running agents.
• SkillsBench regressed — 55.77 against Grok 4.5's 66.03, where 4.5 had ranked first.
• Speed. About 65.5 tokens/second, 17th of 20 models measured. Time to first token regressed badly: 8.7s on Grok 4.5 to 31.2s on 4.6.
• Context. 500K is the smallest of any current frontier model — the rest are at or above 1M.
• Vibe-Code: 10th at 76.2%, behind Muse Spark 1.2, Claude Sonnet 5 and Kimi K3.

Who did xAI leave out of its charts?

xAI's comparison table runs Grok 4.6 against Grok 4.5, GPT-5.6 Sol Max and Claude Fable 5 Max. Claude Opus 5 is absent — the model that actually leads the two rows xAI bolds as wins. Also missing: Kimi K3, Qwen 3.8 Max, Gemini and Meta's Muse Spark 1.2.

In fairness, xAI publishes 7 of 10 rows where Grok 4.6 loses, which is more candid than most launch charts. Read honestly, Fable 5 beats it on 5 of 10 rows and GPT-5.6 Sol wins the two most coding-specific ones.

Is the price-performance pitch still true?

Historically Grok's argument was frontier-adjacent capability at a fraction of the price. In August 2026 that argument is weaker, mostly because of what launched a week earlier.

Meta's Muse Spark 1.2 is roughly half the cost per task with twice the context, and the two are statistically tied on the Vals Index — where Grok 4.6 actually sits 6th at 71.824 against Muse Spark 1.2's 71.877. Note that AA and Vals disagree on the direction of that comparison, which tells you how close it is.

The moat that does survive is real-time data. xAI's first-party x_search tool, at $5 per 1,000 calls, gives licensed access to the X firehose. No competitor has that, and for social listening, news monitoring or anything needing live public sentiment, it is not substitutable.

What are developers actually saying?

Reaction is loud but shallow. Roughly 1,500 comments across Hacker News and Reddit, but only about a dozen people have posted a first-hand run with concrete results. Notably, r/LocalLLaMA has no Grok 4.6 thread at all — the model is closed-weights, so that community has nothing to discuss.

The strongest independent test is a security one. One reviewer ran Grok 4.6 against 16 Hack The Box challenges and reported 14 of 16 solved (80%), zero false positives, $17.31 total, and the fewest steps of any model they had tested. The same author had previously dismissed an earlier Grok release as useless, and now calls 4.6 the best model they have tested on offensive-security work. Grok's comparative willingness to engage with security tasks comes up repeatedly.

Other first-hand data points: a controlled A/B on injected bugs put GPT-5.6 Sol at 8/8 and Grok 4.6 at 7/8; a Codex-CLI head-to-head had Grok 4.6 beat DeepSeek V4 Pro on correctness, but at roughly eleven times the cost.

The consensus placement is tight and consistent: roughly Claude Opus 4.8-class, clearly below Opus 5 and Fable 5, at about a third of the price. And nearly every positive workflow report has the same shape — use an expensive model to plan, then hand implementation to Grok. Sol plans and Grok builds; Opus 5 plans and Grok builds. That "cheapest credible implementer" role is a more defensible summary than any frontier claim.

Recurring praise: price (the top-voted comment on the launch thread is about it), Cursor subscription generosity, speed, and a terse output style people find less padded than rivals.

Recurring complaints: trust and Musk-related objections by a wide margin — including one report of a formal organisation-level ban on the model — plus benchmaxxing scepticism, the 67% cache-read price rise, faster quota burn than 4.5, and a general sense that it is "not really frontier in practice".

One unverified item worth watching rather than repeating: several users report a leaked default xAI API system prompt containing instructions not to write exploits and not to disclose the guidelines themselves, allegedly overriding user-supplied system prompts. We could not confirm it, and it should be treated as a claim rather than a fact until someone does.

Should you use Grok 4.6?

Yes, if you run long-horizon agent workloads where turn count drives cost. Finishing in half the turns of Claude Opus 5 is a genuine economic advantage that per-token tables hide.

Yes, if you need live X data. Nothing else offers it.

Probably not, if latency matters — a 31-second time to first token is difficult in interactive tooling.

Probably not, if you need large context. 500K is last in class, and crossing 200K doubles your bill on the whole request.

Probably not, if you are buying purely on price. Muse Spark 1.2 is cheaper per task with more context, and GPT-5.6 Luna beats Grok on Vals Terminal-Bench at a fraction of the cost.

Not yet, if you are in the EU — there is no EU region.

FAQ

When was Grok 4.6 released?

August 12, 2026, with an underlying checkpoint dated August 10 — 35 days after Grok 4.5.

How much does Grok 4.6 cost?

$2 per million input tokens and $6 per million output, with cached input at $0.50. Prompts of 200K tokens or more are billed at $4/$12 across the entire request.

What is Grok 4.6's context window?

500,000 tokens — unchanged from Grok 4.5, and the smallest of the current frontier models, which are all at or above 1M.

Is Grok 4.6 better than Claude Opus 5?

Not on overall intelligence. Claude Opus 5 scores 63.05 on the Artificial Analysis Intelligence Index against Grok 4.6's 60.92. Grok 4.6 is markedly more turn-efficient, completing AA's agent tasks in roughly half the turns.

Why do Grok 4.6's Terminal-Bench scores differ so much?

Different benchmark versions. xAI reports 26% on Terminal-Bench v3.0; Artificial Analysis reports 88.39% on v2.1. They are not comparable, and v3.0 is substantially harder.

Is there a Grok 4.6 High model?

No. "High" is the default reasoning_effort setting, not a separate model. Grok 4.6 adds a new xhigh level that Grok 4.5 silently ignored.

Did Grok 4.6 get worse at anything?

Yes. LiveBench's early listing shows agentic coding down to 54.2 from Grok 4.5's 56.5, SkillsBench down to 55.77 from 66.03, and time to first token up from 8.7 to 31.2 seconds.

Is Grok 4.6 available in the EU?

No. Only us-east-1 and us-west-2 regions are offered.

What is Grok 4.6's knowledge cutoff?

February 1, 2026.