Claude Opus 5 vs Grok 4.5: A Cheaper Near-Frontier Claude vs a Proven Frontier Flagship

Anthropic's Claude Opus 5 ($5/$25 per 1M tokens, launched July 24, 2026) now tops the Artificial Analysis Intelligence Index — and it lines up here against xAI's Grok 4.5, a frontier model with independently-verified coding numbers and a real deployment history. This guide compares them on independent intelligence, verified coding, price, the effort dial, safety, and which fits your workload.

Figures are labeled by source. Both Intelligence Index scores and Grok 4.5's SWE-bench figure are independent (Artificial Analysis / vals.ai); Opus 5's Frontier-Bench numbers are Anthropic-reported. Verify before committing budget.

TL;DR verdict. Opus 5 leads the independent Intelligence Index at 61 (max effort) versus Grok 4.5's 54 — a clear general-capability gap — at a fixed, transparent $5/$25. Grok 4.5's strength is verified coding: an independently-confirmed 86.6% SWE-bench Verified (vals.ai) and a proven, deployed track record. Choose Opus 5 for best general intelligence per dollar, agents, computer use, and the effort dial; choose Grok 4.5 if you want an independently-verified coding number today or you already build on the xAI stack.

Key takeaways

• Opus 5 leads the index by a clear margin. 61 (max) vs Grok 4.5's 54 on the Artificial Analysis Intelligence Index (July 2026).

• Grok 4.5 has verified coding. 86.6% SWE-bench Verified, independently confirmed by vals.ai.

• Opus 5 pricing is fixed and public. $5/$25; Grok 4.5's rate varies by tier — confirm current.

• Opus 5 adds an effort dial. Low/medium/high/max; max tops the board, cheaper settings still beat most rivals.

• Both are frontier-class; ecosystem and the proven-vs-general split decide it.

The specs and price, side by side

• Vendor — Opus 5: Anthropic; Grok 4.5: xAI.

• Price per 1M (in / out) — Opus 5: $5 / $25; Grok 4.5: varies by xAI tier (confirm).

• Artificial Analysis Intelligence Index — Opus 5 (max): 61 (#1 of 170); Grok 4.5: 54. [Artificial Analysis, July 2026]

• SWE-bench Verified — Opus 5: — (no separate audited figure yet); Grok 4.5: 86.6% (independently verified, vals.ai).

• Frontier-Bench v0.1 (vendor) — Opus 5: 43.3%; Grok 4.5: not reported on this suite.

• Effort control — Opus 5: low/medium/high/max; Grok 4.5: standard.

• Context — both large-context frontier models.

Benchmark deep-dive: general lead vs verified coding

On general capability, Opus 5 has a clear, independent edge: the Artificial Analysis Intelligence Index puts Opus 5 (max) at 61, seven points above Grok 4.5's 54 — a meaningful gap on a third-party composite of reasoning, math, coding, and knowledge. That's the strongest single signal that Opus 5 is the more capable generalist here.

Grok 4.5's advantage is a specific, checkable coding number: an 86.6% SWE-bench Verified independently confirmed by vals.ai, plus a real record of shipping across xAI's products. Opus 5's coding case rests on the index lead and Anthropic's Frontier-Bench v0.1 (43.3%) and OSWorld 2.0 computer-use results — strong, but its audited SWE-bench figure isn't published. So Opus 5 wins general intelligence outright; Grok 4.5 keeps the verified coding-accuracy citation.

The effort dial and cost

Opus 5's low/medium/high/max effort setting is a real cost lever: run routine calls cheap and dial up to max (the leaderboard-topping setting) only for hard requests. Its pricing is fixed and public — a 20,000-in / 3,000-out call is about $0.175 ($0.10 input + $0.075 output). Grok 4.5's per-token pricing varies by plan, so model your own workload against xAI's current rate before comparing totals; for output-heavy agent traffic, Opus 5's flat $25 output is easy to budget.

How to access each

Opus 5 is on Claude.ai (Max default, Pro's strongest), the Claude API, Claude Code, and Claude Cowork, with the effort level as an API parameter. Grok 4.5 is available through xAI's API and products. Vendor-neutral teams can run both behind one OpenAI-compatible endpoint and route per task; committed stacks usually pick the native option.

Three real-world scenarios

1. Coding agents needing a verified score

Grok 4.5's independently-verified 86.6% SWE-bench Verified is the defensible pick when a stakeholder wants proof. Opus 5 leads the general index but lacks a published audited SWE-bench figure.

2. General reasoning, agents, and computer use

Opus 5's clear index lead (61 vs 54), OSWorld 2.0 results, effort dial, and Claude tooling make it the stronger general default — validate on your own tasks.

3. Teams inside an existing stack

Already on Claude points to Opus 5; on the xAI stack points to Grok 4.5. Integration gravity usually beats a benchmark delta unless the gap is decision-changing.

Safety and alignment

Anthropic calls Opus 5 its most aligned Opus, with cyber classifiers expected to intervene about 85% less often than Fable 5 — typically fewer false refusals on legitimate security or research work. xAI applies its own approach to Grok 4.5, which has historically been positioned as less restrictive; test both against your content and compliance requirements rather than assuming either posture fits.

When not to use each

Don't pick Opus 5 when you need an independently-verified coding number today — Grok 4.5's 86.6% (vals.ai) is the stronger evidence. Don't assume Grok 4.5 is cheaper without checking current xAI pricing against Opus 5's flat $5/$25. And don't switch ecosystems for a modest gap.

Pricing worked example: fixed vs tier-based

Opus 5's pricing is fixed and public, which makes budgeting simple; Grok 4.5's varies by xAI plan and tier, so you must model against its current rate. On Opus 5, a mixed workload of 500,000 calls at 10,000 in / 2,000 out costs 500k × ($0.05 + $0.05) = about $50,000/month at flat rate — and less if you run routine calls below max effort. For Grok 4.5, plug xAI's current per-token or subscription pricing into the same call profile; depending on tier it may land above or below Opus 5, which is exactly why you should compute it rather than assume. The practical takeaway: Opus 5 gives you a predictable, effort-tunable bill and the #1 general index; Grok 4.5's cost-competitiveness depends on which xAI tier you qualify for.

Migrating or running both across vendors

Like any cross-vendor choice, integration gravity dominates. If you already build on xAI, Grok 4.5 avoids re-plumbing; if you're vendor-neutral, run both behind one OpenAI-compatible endpoint and route by need — send jobs that require a verified coding number (Grok 4.5's independently-confirmed 86.6% SWE-bench Verified) to Grok, and general reasoning, computer-use, or output-heavy work to Opus 5. Use a shadow evaluation on your own tasks to decide the split, and revisit it as both models and xAI's pricing evolve.

Context, limits, and what to watch

Both are large-context frontier models. The two things to watch here are verification and posture: watch for an independent SWE-bench Verified score for Opus 5 (which would match Grok 4.5's proven coding evidence), and note the safety difference — Anthropic emphasizes Opus 5's alignment and reduced false refusals, while Grok has historically been positioned as less restrictive, which may matter for your content and compliance needs. As always, the 61 index figure is Opus 5's max effort setting; benchmark the level you'll actually run, and re-check both leaderboards and xAI pricing before committing.

FAQ

Is Claude Opus 5 better than Grok 4.5?

On the independent Artificial Analysis Intelligence Index, Opus 5 (max) leads clearly at 61 versus Grok 4.5's 54. Grok 4.5 keeps a verified coding number (86.6% SWE-bench Verified, vals.ai) that Opus 5 hasn't been separately scored on. General #1 vs verified coder.

Which is cheaper?

Opus 5 is a flat $5/$25 per 1M tokens; Grok 4.5's rate varies by tier, so compare against xAI's current pricing for your workload.

Which is better for coding?

For a verified coding number today, Grok 4.5 (86.6% SWE-bench Verified). Opus 5 leads the general index and is in Claude Code, but its audited SWE-bench figure isn't published.

What is the effort dial?

A per-request low/medium/high/max setting on Opus 5 that trades cost for capability; max tops the leaderboard.

Does Opus 5 have independent benchmarks?

Yes — Artificial Analysis now ranks Opus 5 (max) #1 at 61 on its Intelligence Index. A separate audited SWE-bench Verified figure isn't published yet.

How should I choose?

Default to your stack; use Grok 4.5 when you need a verified coding citation, Opus 5 for best general intelligence per dollar and computer-use tasks — confirm on your own eval.

Can I run both?

Yes — route Opus 5 and Grok 4.5 through one OpenAI-compatible endpoint and compare per task.

Decision checklist

• Pick Opus 5 if: you want the clear general-intelligence lead (61 vs 54), fixed and effort-tunable pricing, computer-use depth (OSWorld 2.0), or Claude tooling.

• Pick Grok 4.5 if: you need an independently-verified coding number today (86.6% SWE-bench Verified, vals.ai), you're on the xAI stack, or its pricing tier is favorable for your volume.

• Run both if: you're vendor-neutral — route verified-coding jobs to Grok 4.5 and general reasoning/computer-use work to Opus 5.

The index gap is seven points — is that decisive?

It's meaningful for general reasoning (61 vs 54 on an independent composite), so for broad tasks Opus 5 is the stronger generalist. But Grok 4.5's verified 86.6% SWE-bench Verified is a specific, checkable coding result that a general index doesn't replace — match the metric to your job.

Which is cheaper?

Opus 5 is a flat $5/$25 with an effort dial, so it's predictable; Grok 4.5's rate varies by xAI tier, so compute it for your volume before assuming. Neither is universally cheaper — it depends on your plan and token mix.

Which is safer / less restrictive?

Anthropic positions Opus 5 as its most aligned Opus with fewer false refusals on legitimate work; Grok has historically been positioned as less restrictive. Which is "better" depends on your content policy — test both against your actual prompts.

Does Opus 5 have a verified coding score yet?

Not a separate audited SWE-bench Verified number as of this writing — its coding case rests on the #1 general index plus vendor Frontier-Bench v0.1 (43.3%). Grok 4.5's 86.6% is independently confirmed, so for a citable coding figure Grok leads today.

Can I use Grok 4.5 and Opus 5 behind one integration?

Yes — route both through an OpenAI-compatible endpoint and switch per task without maintaining two SDKs.

Do they have similar context windows?

Both are large-context frontier models suitable for long documents and codebases; Opus 5 is Opus-family 1M-class. For most workloads either handles your inputs, so context is rarely the deciding factor between them.

Which should I default to if I'm undecided?

Default to Opus 5: it leads the independent general index (61 vs 54), has fixed and effort-tunable pricing, and integrates with Claude Code/Cowork. Switch to or add Grok 4.5 specifically when you need its verified coding number or you're committed to the xAI stack.

Which to choose by team type

Startups and product teams: if you want predictable billing and the strongest general model, Opus 5's fixed $5/$25, effort dial, and #1 index (61 vs 54) are the low-friction default. Choose Grok 4.5 if your team is already on the xAI stack or you specifically need its verified coding result in your pitch.

Enterprises with a compliance paper trail: Grok 4.5's independently-verified 86.6% SWE-bench Verified (vals.ai) is a citable coding number; Opus 5 leads the general index but lacks a published audited SWE-bench figure. If your procurement wants verified coding evidence, that favors Grok today; if it wants the top general model and managed alignment, Opus 5.

Individual developers: Opus 5's general lead, computer-use depth, and Claude Code integration make it the stronger all-round assistant; Grok 4.5 appeals if you value its less-restrictive posture or are already in the xAI ecosystem.

Safety-sensitive deployments: Anthropic emphasizes Opus 5's alignment and reduced false refusals, which suits regulated or brand-sensitive use; Grok's historically looser posture may suit teams that found other models over-refusing. Test both against your own content policy rather than assuming.

Bottom line

Claude Opus 5 now leads the independent Artificial Analysis Intelligence Index by a clear margin (61 vs Grok 4.5's 54), at a fixed $5/$25 with an effort dial and a safer alignment profile. Grok 4.5 keeps a verified coding number — 86.6% SWE-bench Verified (vals.ai) — and a proven deployment record. For best general intelligence per dollar, agents, and computer use, Opus 5; for a verified coding citation or an xAI-native stack, Grok 4.5. Route both — and every rival flagship — through one OpenAI-compatible endpoint at OrcaRouter.