xAI launched Grok 4.6 on August 12 with a pitch that’s hard to ignore: frontier-class intelligence at a fraction of what Anthropic and OpenAI charge. $2 per million input tokens, $6 per million output. Run the math on a real coding-agent workload and Grok 4.6 costs $600 a month for the same 100 million output tokens that run $3,000 on GPT-5.6 Sol. That’s not a rounding difference. That’s an 80% discount on the same class of work.

Here’s the part xAI’s own launch materials don’t lead with: on the ten-category eval table xAI itself published, Claude Fable 5 Max still wins more categories than either competitor. The company selling you the cheap option is the same company whose data shows the expensive option is still winning on quality. Both of those things are true at once, and buyers need to know which one matters for their workload before they touch a router config.

Quick Verdict

Aspect	Grok 4.6	GPT-5.6 Sol	Claude Fable 5 Max
Pricing (in/out per 1M tokens)	$2 / $6	$5 / $30	$10 / $50
100M output tokens/month cost	~$600	~$3,000	~$5,000
Artificial Analysis Intelligence Index	61	61	62
Context window	500K	1.05M	1M
Wins most categories on xAI’s own eval table	No	No	Yes
Best for	Cost-capped agent fleets, knowledge work, legal	Long-run terminal/agentic coding	Workloads where quality is the constraint, not spend

Bottom line: Grok 4.6 is the cheapest frontier-adjacent model on the market by a wide margin, and it’s genuinely competitive on the Intelligence Index. It is not the best model in this comparison, by xAI’s own published numbers, and the context window and pricing structure both narrow the gap between “cheap” and “cheap enough for your actual workload.”

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What Grok 4.6 Actually Is

Grok 4.6 shipped August 12, positioned by xAI as a frontier model that doesn’t require frontier pricing. On the Artificial Analysis Intelligence Index — a composite score across reasoning, coding, and knowledge benchmarks that we’ve used to compare every flagship release this year — Grok 4.6 lands at 61. That ties GPT-5.6 Sol, OpenAI’s general-purpose frontier model, and sits one point behind Claude Fable 5 Max’s 62.

A one-point gap on a composite index is close enough to call a tie in most conversations. It is not, on its own, the interesting number here. The interesting number is what happens when you put that near-tie next to the price tag.

The Pricing Gap Is Real, and It’s Large

$2 per million input tokens and $6 per million output. Compare that to GPT-5.6 Sol at $5/$30 and Claude Fable 5 at $10/$50, and Grok 4.6 isn’t just cheaper — it’s operating in a different pricing bracket entirely.

Run it against a workload that actually matters: a team running coding agents that burn through 100 million output tokens a month, which is a credible footprint for an agentic engineering org, not an edge case. On Grok 4.6, that’s roughly $600 a month. On GPT-5.6 Sol, roughly $3,000. That’s an 80% reduction for output-heavy work, and it’s the exact math behind the headline xAI wants written about this launch.

For teams running high-volume, cost-sensitive agent fleets — customer support triage, document classification, first-pass code review — that gap is not a marginal optimization. It’s the difference between a workload that pencils out and one that doesn’t. We’ve seen this pattern before: MiniMax M3 made the same pitch in June at an even steeper discount, and the lesson from that launch holds here too. A large price gap against frontier peers is real and worth taking seriously. It is also, by itself, not the whole story.

The Catch: Context Window and Pricing Structure

Grok 4.6 ships with a 500,000-token context window. That’s the smallest of the three models in this comparison, by a meaningful margin — GPT-5.6 Sol offers 1.05 million tokens, Claude Fable 5 Max offers 1 million. For single-turn queries and short agentic loops, that ceiling rarely matters. For workloads that lean on long-document analysis, large codebase context, or extended multi-turn agent sessions, it’s a real constraint the other two models don’t share.

The second catch is buried in xAI’s own pricing page, not in a competitor’s marketing: Grok’s per-token rate doubles past the 200,000-token mark. The headline $2/$6 pricing is the rate for the first 200K tokens of context in a given call. Push past that threshold — which a long agentic coding session or a large document-ingestion task will do without much effort — and the effective cost climbs toward $4/$12. That’s still cheaper than GPT-5.6 Sol. It is not the 80%-cheaper number from the top of this article once your actual usage pattern crosses the threshold xAI set the discount around.

Neither of these facts makes Grok 4.6 a bad model. They make the “80% cheaper” framing a best-case number that depends on your context length staying inside a specific window. Read your own token logs before you believe the discount applies to your workload wholesale.

Where xAI’s Own Eval Table Tells a Different Story

This is the part worth sitting with. xAI published a ten-row category breakdown alongside the Grok 4.6 launch — the company’s own data, not a third party’s. Across those ten categories, Claude Fable 5 Max wins the most.

Grok 4.6 does win real categories, and they’re not throwaway ones. It takes knowledge work and legal — tasks that reward broad factual recall and structured document reasoning, exactly the kind of workload where Grok’s real-time data access and lower cost per query compound into a genuine advantage. If your primary use case sits in either of those buckets, Grok 4.6’s win there is backed by the company’s own published numbers, not just marketing copy.

Where it loses is more specific, and more relevant to anyone routing agentic coding workloads: Grok 4.6 falls to GPT-5.6 Sol on Terminal-Bench v3.0 by roughly 8.6 points. Terminal-Bench measures exactly what it sounds like — a model’s ability to complete real terminal and CLI-driven tasks, the bread-and-butter work of coding agents operating in a shell. An 8.6-point gap on that specific benchmark is not a rounding error for a team building agent infrastructure around terminal execution.

So the eval table draws a cleaner line than the pricing page does. Grok 4.6 for knowledge work and legal, at a fraction of the cost. GPT-5.6 Sol for terminal-driven agentic coding, where it beats Grok 4.6 on xAI’s own benchmark. Claude Fable 5 Max for the workloads where the most categories on the table point in its direction, at a price that assumes you’re already treating quality as the binding constraint rather than spend.

Pricing Comparison

Metric	Grok 4.6	GPT-5.6 Sol	Claude Fable 5 Max
Input (per 1M tokens)	$2	$5	$10
Output (per 1M tokens)	$6	$30	$50
Context window	500K	1.05M	1M
Pricing past 200K context	Doubles (~$4/$12)	Flat	Flat
100M output tokens/month	~$600	~$3,000	~$5,000

The output-token gap is where this comparison actually gets decided for most buyers. Input tokens are cheap everywhere; output is where agentic workloads spend their budget, since every tool call, code diff, and generated response counts against it. At $6 per million output tokens, Grok 4.6 is competitive with models a full tier below frontier pricing. At $50 per million, Claude Fable 5 Max is charging a premium that only pencils out if the capability gap on your specific workload is wide enough to justify it — which, per xAI’s own eval table, it often is.

How to Decide

Choose Grok 4.6 if:

• Your workload is knowledge work, legal document analysis, or research — the categories xAI’s table shows it actually winning
• You’re running high-volume, cost-capped agent fleets where an 80% reduction in output cost changes whether the project ships
• Your typical context length stays comfortably under 200K tokens per call, so the doubled pricing tier rarely triggers

Choose GPT-5.6 Sol if:

• You’re running terminal-driven agentic coding workflows, where it beats Grok 4.6 by roughly 8.6 points on Terminal-Bench v3.0
• You need the largest context window of the three, at 1.05 million tokens
• You want frontier-tier pricing without paying the top-of-market premium Fable 5 Max charges

Choose Claude Fable 5 Max if:

• Quality is the binding constraint on your workload, not per-token spend
• Your use case falls into one of the categories where xAI’s own table shows it winning outright
• You’ve already run the Fable 5 saga through your procurement process and have a spend line built around premium frontier pricing

The Stuff Nobody’s Saying Out Loud

xAI built a genuinely compelling pricing story and then published benchmark data that undercuts its own headline. That’s not a hostile read — it’s the plain result of putting the eval table next to the press release. A company doesn’t have to be lying about pricing to be selling a story that’s more flattering than its own data supports. Grok 4.6 is real progress: a near-frontier Intelligence Index score at a price point none of the other two get close to. It is not, on xAI’s own numbers, the best model in this comparison for coding-agent work specifically, and the doubled pricing past 200K tokens means the 80%-cheaper framing needs a caveat most buyers won’t read past the headline to find.

The buyers this hurts are the ones who route budget decisions off a single number — “80% cheaper” — without checking whether their workload lands in the categories where that discount actually holds up against quality. Read the eval table before the pricing page. The pricing page is the marketing. The eval table is xAI grading its own homework, and it’s still not giving itself the top score.

Frequently Asked Questions

Is Grok 4.6 cheaper than GPT-5.6 Sol and Claude Fable 5?

Yes, substantially. Grok 4.6 prices at $2 per million input tokens and $6 per million output, versus GPT-5.6 Sol’s $5/$30 and Claude Fable 5’s $10/$50. For a workload running 100 million output tokens a month through coding agents, that works out to roughly $600 for Grok 4.6 versus $3,000 for GPT-5.6 Sol — an 80% reduction. The discount narrows once a session’s context passes 200,000 tokens, where Grok’s own pricing doubles.

Does Grok 4.6 beat GPT-5.6 Sol and Claude Fable 5 on benchmarks?

Not consistently. On the Artificial Analysis Intelligence Index, Grok 4.6 scores 61, tying GPT-5.6 Sol and landing one point behind Claude Fable 5 Max’s 62. On xAI’s own published ten-category eval table, Claude Fable 5 Max wins the most categories overall. Grok 4.6 wins knowledge work and legal outright, but loses Terminal-Bench v3.0 — a benchmark for agentic coding and CLI tasks — to GPT-5.6 Sol by about 8.6 points.

What is Grok 4.6’s context window?

500,000 tokens — the smallest of the three models covered here. GPT-5.6 Sol offers 1.05 million tokens and Claude Fable 5 Max offers 1 million. Grok’s pricing also doubles once a single call’s context passes 200,000 tokens, which matters more for long-document or extended-session workloads than the raw ceiling does.

Which model is best for coding agents specifically?

Based on xAI’s own Terminal-Bench v3.0 results, GPT-5.6 Sol beats Grok 4.6 by roughly 8.6 points on the benchmark most directly tied to terminal and CLI-driven agent work. Claude Fable 5 Max wins the broadest set of categories on xAI’s published table overall. Grok 4.6’s price advantage is real, but for workloads that live in a terminal, it isn’t the benchmark leader among these three.

Should my team switch to Grok 4.6 to cut AI spend?

It depends on where your workload actually sits. If it’s knowledge work, legal analysis, or high-volume tasks with context comfortably under 200,000 tokens, Grok 4.6’s pricing and its own category wins make a real case. If it’s terminal-driven agentic coding or work where output quality is the binding constraint, xAI’s own eval table points toward GPT-5.6 Sol or Claude Fable 5 Max instead. Route by workload category, not by headline discount.

Is Claude Fable 5 Max the same model that got pulled by export control in June?

It’s the same product line. The original Claude Fable 5 launched June 9 and was pulled globally by a Commerce Department export control directive on June 12, three days after launch. Pricing referenced in this comparison — $10 per million input tokens, $50 per million output — matches Fable 5’s original published rate.

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Last updated: August 16, 2026. Sources: xAI — Grok 4.6 announcement · Artificial Analysis Intelligence Index.

Related reading: Claude Fable 5 Review: Anthropic’s Best Model Yet · Fable 5 Pulled: What Buyers Need to Know · OpenAI’s GPT-5.6-Cyber Crosses Its Own Risk Line · Grok 4.20 Review: xAI’s 4-Agent System Tested · MiniMax M3 Review: Frontier AI at 1/10th the Cost