Grok 4.5 vs Claude: Benchmarks & Pricing

The Grok 4.5 vs Claude decision, for coding and agent workloads in July 2026, comes down to price and availability, not raw capability, because the two are close enough that neither wins on capability alone. On xAI's own published benchmarks, Grok 4.5 wins two and loses two against Claude Opus 4.8, while costing $2 per million input tokens and $6 per million output against Opus 4.8's roughly $5 and $25.

That is the whole story in one line. The rest of this piece is the detail behind it, because the internet filled up with biased versions of this comparison the same day Grok 4.5 launched, and a coding or agent decision deserves the actual numbers.

Key Takeaways:

• Grok 4.5 beats Opus 4.8 on DeepSWE 1.0 and Terminal-Bench 2.1; Opus 4.8 wins DeepSWE 1.1 and SWE-Bench Pro. Two wins each.
• Grok 4.5 is cheaper on sticker price ($2/$6) and claims roughly 2x token efficiency, which widens the real cost gap.
• Claude Sonnet 5 is the closer price rival at $2/$10 intro ($3/$15 standard), with a 1M context window and worldwide availability.
• Grok 4.5 is EU-blocked at launch; Claude models are not. Availability, not benchmarks, may be your real constraint.

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Grok 4.5 vs Claude: The Short Verdict

Here is the Grok 4.5 vs Claude comparison table, with every number pulled from the vendors' own published material. Benchmark figures come from xAI's launch chart as reported in independent coverage; pricing is from each provider's docs.

Factor	Grok 4.5	Claude Opus 4.8	Claude Sonnet 5
Input price (per M tokens)	$2	~$5	$2 intro / $3 standard
Output price (per M tokens)	$6	~$25	$10 intro / $15 standard
Context window	500K	Opus-class	1M
Positioning	Coding, agents, knowledge work	Frontier reasoning	Cheaper agentic Sonnet
EU availability at launch	Blocked (mid-July target)	Available	Available
Standout trait	Token efficiency, Cursor-tuned coding	Top-tier reasoning depth	1M context, low price

Intro pricing for Sonnet 5 runs through August 31, 2026. Opus 4.8 prices are approximate and worth checking against the live models overview before you budget.

What this resolved: no model sweeps the table. What it left unsolved: the right pick depends on your workload and where you operate, covered below.

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The Opus-Class Claim, Tested Against xAI's Own Numbers

Elon Musk called Grok 4.5 an "Opus-class model, but faster, more token-efficient and lower cost" in his own launch post, and added that xAI's internal assessment is that it is "roughly comparable to Opus 4.7, but much faster." Marketing claims are marketing claims. The useful test is xAI's own benchmark chart, which pits Grok 4.5 directly against Opus 4.8.

Benchmark	Grok 4.5	Opus 4.8	Winner
DeepSWE 1.0	62.0%	55.75%	Grok 4.5
DeepSWE 1.1	53%	59%	Opus 4.8
Terminal-Bench 2.1	83.3%	78.9%	Grok 4.5
SWE-Bench Pro	64.7%	69.2%	Opus 4.8

Source: xAI's published comparison, as broken down here. Two wins each. These are the developer-published system-card style numbers, so treat them as directional, not gospel, and remember that xAI chose which benchmarks to show.

The honest reading of "Opus-class" is that it holds. Grok 4.5 trades blows with a genuine frontier model on hard coding and terminal-agent tasks. It is not a blowout in either direction. Where Grok pulls ahead is the SWE-Bench Pro efficiency story: xAI reports Grok 4.5 resolves those tasks using an average of about 15,954 output tokens versus 67,020 for Opus 4.8 at its max setting, a roughly 4.2x gap. That is xAI's own measurement, so weight it accordingly, but if it holds up in your workload, it changes the cost math more than the sticker price does.

Raj, a backend engineer running an autonomous refactor agent across a 400-file monorepo, cared about exactly this. His agent loops thousands of times per run, so output tokens per solved task drive his bill far more than the headline rate. On his own eval set, Grok 4.5 finished comparable tasks in noticeably fewer steps, which is the practical version of the efficiency claim.

What this resolved: the Opus-class label is fair, not hype. What it left unsolved: benchmarks are the vendor's chosen slice; your codebase is the real test.

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Independent Benchmarks, Not Just xAI's Chart

xAI picked which benchmarks to show, so the stronger evidence is third-party. Two independent evaluations landed within days of launch, and they mostly back the Opus-class claim while adding a caveat xAI's chart left out.

Snorkel AI ran Grok 4.5 on its GDPval+ set of roughly 2,000 professional workplace-reasoning tasks. Grok 4.5 posted a 29% mean pass rate, ahead of GPT-5.5 at 22% and Opus 4.8 at 21%. The lead was widest in judgment-heavy domains: legal work (40% versus 27 to 28%), education (58% versus 35 to 42%), healthcare (35% versus 23 to 25%), and QA analysis (37% versus 19 to 27%). On this independent professional-work test, Grok did not just match Opus, it led it.

Artificial Analysis's AutomationBench-AA tells a more nuanced story. Grok 4.5 ranked first at 51.4%, edging Claude Fable 5 (48.6%) and Opus 4.8 (48.5%), at roughly $0.34 per task. But it broke more rules to get there: 0.63 guardrail violations per task against Opus 4.8's 0.55. For an autonomous agent with write access, a higher violation rate is a real cost, not a footnote. The speed and price came with slightly looser guardrails, which matters more the less a human is watching.

The same evaluation clocked Grok 4.5 at about $0.49 per completed task, which Artificial Analysis called nearly 90% cheaper than the models ranked above it, putting it on the Pareto frontier for performance versus cost. That figure comes from a source that is not xAI, and it lines up with the per-task math above.

What this resolved: independent tests back the Opus-class claim, and on professional-judgment work Grok actually leads. What it left unsolved: Grok's higher guardrail-violation rate is a genuine risk for unattended agents, so the win is not free.

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Pricing Reality: Sticker Price vs What You Actually Pay

Sticker price is the trap in every model comparison. Two things bend the real number.

First, Grok 4.5's token efficiency. If the model genuinely solves tasks in fewer output tokens, a $6 output rate can beat a nominally cheaper competitor that rambles. xAI leans hard on this, claiming "twice greater token efficiency" than leading rivals. It is a vendor claim, so verify it on your own traffic, but the direction is real.

Make it concrete with the one comparison where both token counts are public. On SWE-Bench Pro, xAI's numbers put Grok 4.5 at about 15,954 output tokens per solved task and Opus 4.8 at 67,020. Price those at each model's output rate and the gap on output cost alone is not the 4.2x of the token count, it is far wider: roughly $0.10 per solved task on Grok (15,954 tokens times $6 per million) versus about $1.68 on Opus (67,020 times $25 per million), close to a 17x difference. Fewer tokens multiplied by a lower rate compounds. That is output tokens only, on a single benchmark, using xAI's own measurements, so treat it as illustrative rather than a guarantee, but it is why a $6 sticker can undercut a premium model by far more than the rate card suggests.

Second, and pointing the other way, Sonnet 5's new tokenizer. Anthropic's docs state Sonnet 5 produces approximately 30% more tokens for the same text than Sonnet 4.6, with per-token pricing unchanged. So Sonnet 5's effective cost per request runs higher than its rate card suggests, and higher still after intro pricing ends. We did the full arithmetic in a separate breakdown of Sonnet 5's tokenizer cost change.

Put those together and the effective-cost ranking is not the same as the sticker ranking. Grok 4.5's real cost trends below its rate card; Sonnet 5's trends above. Opus 4.8 stays the premium option you reach for when reasoning depth is worth paying for.

What this resolved: effective cost, not sticker price, is the number to compare. What it left unsolved: you only get your real number by running your actual prompts through each.

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Grok 4.5 vs Sonnet 5: The Cheaper-Agent Matchup

Opus 4.8 is the reasoning flagship, but the more relevant fight for most teams is Grok 4.5 against Claude Sonnet 5, because both are pitched as cheaper ways to run agents. Sonnet 5 launched June 30, 2026 with performance close to Opus 4.8, a 1M token context window, and $2/$10 introductory pricing.

The split is clean. Grok 4.5 wins on raw token cost and Cursor-tuned coding. Sonnet 5 wins on context window (1M versus 500K) and on availability, since it has no EU block and ships across the Claude API, AWS, Google Cloud, and Microsoft Foundry. If your agent needs to hold a huge codebase or document set in context, the 1M window is decisive. If your agent is a tight IDE-coding loop where cost per task rules, Grok 4.5 is compelling.

One more angle from the community that is easy to miss: the model often matters less than the system around it. As one widely-upvoted r/ChatGPT thread put it, an average model with perfect context about your work can outperform the best model that knows nothing about you. For real agent workflows, memory and tool wiring frequently beat a two-point benchmark edge.

What this resolved: Grok 4.5 vs Sonnet 5 comes down to cost-and-coding versus context-and-availability. What it left unsolved: the surrounding agent system can outweigh the model choice entirely.

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Which Model to Pick by Workload

Skip the "best model" framing and match to the job.

• IDE-heavy coding: Grok 4.5 first. It was trained with real Cursor developer session data, including debugging traces and multi-file diffs, and it shows on terminal and SWE benchmarks. Cursor confirmed the training partnership directly, calling it their most powerful model yet.
• Long-context work: Claude Sonnet 5. A 1M context window holds far more codebase, transcript, or document set than Grok's 500K, even accounting for the denser tokenizer.
• Deepest reasoning on hard, ambiguous problems: Opus 4.8. When a wrong answer is expensive and you want the strongest reasoning, pay for the flagship.
• High-volume autonomous agent runs where cost dominates: Grok 4.5 if you can reach it, Sonnet 5 if you need worldwide availability or the bigger window.

Elena, a fractional CTO advising three startups, runs this exact triage. IDE work goes to Grok where the team has access, long-document analysis goes to Sonnet 5, and the one gnarly architecture decision per month goes to Opus. She routes by task, not by loyalty, and her monthly bill dropped because of it.

What this resolved: a workload-to-model map you can act on. What it left unsolved: availability can override all of it, which is the next section.

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The EU Gap and Other Availability Fine Print

The cleanest benchmark win means nothing if you cannot call the model. Grok 4.5 is not available in the EU at launch, with access expected mid-July 2026. We cover the EU situation in depth in Grok 4.5 is not available in the EU: what to do.

Claude Sonnet 5 and Opus 4.8 carry no such block. For an EU team choosing today, the comparison partly resolves itself: the model you can actually run beats the one you cannot, at least until mid-July. Availability is not a footnote in July 2026. It is a first-order input.

What this resolved: for EU teams, availability may pre-decide the pick. What it left unsolved: once Grok opens in the EU, you are back to comparing on merits.

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FAQ

Is Grok 4.5 better than Claude for coding?

On xAI's own benchmarks, they split: Grok 4.5 wins DeepSWE 1.0 and Terminal-Bench 2.1, Opus 4.8 wins DeepSWE 1.1 and SWE-Bench Pro. Grok is cheaper and more token-efficient. Run both on your codebase before committing.

Is Grok 4.5 really Opus-class?

Based on the published numbers, yes, in the sense that it trades blows with Opus 4.8 on hard coding tasks rather than trailing it. It is not clearly better; it is competitive at a lower price.

Grok 4.5 vs Sonnet 5, which is cheaper?

Grok 4.5 has the lower sticker rate ($2/$6 vs Sonnet 5's $3/$15 standard). But Sonnet 5's intro pricing ($2/$10 through Aug 31) and Grok's token-efficiency claim both move the effective number. Compare on your real traffic.

Which has the bigger context window?

Claude Sonnet 5, at 1M tokens, versus Grok 4.5's 500K.

Can I use Grok 4.5 in Europe?

Not at launch. EU availability is expected around mid-July 2026. Until then, Claude models are the available frontier option in the EU.

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How to Route Coding and Agent Work Without Betting on One Model

The teams that win this cycle do not pick a forever-model. They route by workload and stay ready to switch as prices and availability move, which in 2026 they do monthly.

The friction is that routing across models usually means juggling API keys, SDKs, and billing. If you would rather describe the outcome and let an agent handle it, MoClaw runs Claude Sonnet 5 for agent workflows from July 10, 2026, with no API setup, worldwide including the EU. Start there for the work you need done today, and slot Grok 4.5 into your coding stack once it clears the EU gate and you have benchmarked it on your own repo. Pick by the task in front of you, not by whose launch tweet was loudest.