Grok 4.5 wins on price ($2 vs $5/1M input). Claude Opus 5 wins on coding (100 vs 94) and writing quality and context window (1M vs 500K). For most workflows, Claude Opus 5 is the stronger default — best premium model for agentic coding — near-fable 5 quality at half the price.
The safest Grok 4.5 vs Claude Opus 5 default, the cheaper option worth trying first, and the specialist pick — before you read the detail below.
Claude Opus 5 is the strongest answer here for Grok 4.5 vs Claude Opus 5 — pick it when quality of output matters more than the $5.00/1M/1M input you pay for it.
Grok 4.5 handles the same job for about 73% less per token. Start here and only move up if the output is not good enough.
Grok 4.5 is the fastest of these for Grok 4.5 vs Claude Opus 5 — worth it when latency is what the reader notices, not the last few points of reasoning depth.
Claude Opus 5 leads on coding with a score of 100 vs 94 for Grok 4.5.
Claude Opus 5 has the larger context window: 1M vs 500K for Grok 4.5.
Grok 4.5 is cheaper at $2/1M input tokens vs $5/1M for Claude Opus 5.
Choose Claude Opus 5 for complex agentic coding and enterprise agent workflows. Its coding and research scores are what carry the recommendation here.
Switch to Grok 4.5 when your work is mostly fast and token-efficient coding agents; on that narrower brief it is the better tool.
Grok 4.5 is the more cost-efficient option at $2/1M input — Claude Opus 5 costs 3x more per input token, so the gap is worth taking seriously wherever token volume rather than peak quality drives the bill.
Switch the scoring lens to see whether the Grok 4.5 vs Claude Opus 5 answer changes when cost, speed, or long-document depth leads the decision.
Anthropic / Premium / Sep 3, 2026
Best premium model for agentic coding — near-Fable 5 quality at half the price.
Ranks models by the broadest mix of coding, writing, research, and long-context usefulness.
You need fast interactive latency (Sonnet 5 is quicker and one-fifth the price) or absolute frontier ceiling (Fable 5).
Where the Grok 4.5 vs Claude Opus 5 recommendation shifts once you weigh price or latency differently.
Best cost-per-solved-task coding agent — efficiency over ceiling.
Best premium model for agentic coding — near-Fable 5 quality at half the price.
List prices and published scores — the numbers this page's pick is built from.
| Model | Input | Output | Est. month | Context | Speed | Coding | Writing | Research |
|---|---|---|---|---|---|---|---|---|
| Claude Opus 5Anthropic | $5.00/1M | $25.00/1M | $100 | 1M tokens | Deliberate | 100 | 96 | 98 |
| Grok 4.5xAI | $2.00/1M | $6.00/1M | $32 | 500k tokens | Fast | 94 | 72 | 84 |
Scores out of 100 — how we evaluate models. “Est. month” is 10M in / 2M out at list price: a ceiling, no discounts.
Why each one is on the shortlist for Grok 4.5 vs Claude Opus 5, what it is genuinely good at, and where we would steer you away from it.
Ranked first here for Grok 4.5 vs Claude Opus 5: 100/100 on coding, with the widest margin of anything in this line-up.
Anthropic's flagship-tier Opus that comes close to Claude Fable 5's frontier intelligence at half the price — the new default for complex agentic coding and enterprise agents.
You need fast interactive latency (Sonnet 5 is quicker and one-fifth the price) or absolute frontier ceiling (Fable 5).
The new premium coding default. Opus 5 takes the SWE-bench Verified lead from Opus 4.8 at the same $5/$25 price, and gets within half a point of Fable 5 on agentic coding at half the cost. Choose Fable 5 only when absolute frontier intelligence matters more than budget.
Full pricing, benchmark table and release notes on the Claude Opus 5 page.
The cost-conscious pick for Grok 4.5 vs Claude Opus 5, about 73% less per token than Claude Opus 5 than the top choice while holding 94/100 on coding.
xAI's first coding- and agent-focused model — the first full-scale deployment of the 1.5T-parameter V9 MoE base, trained with real developer-session data from Cursor.
You need the highest solve rate per attempt or verified low hallucination — Claude Opus 5 is the safer premium pick.
The efficiency play among coding agents. Grok 4.5 wins on cost-per-solved-task and marathon sessions, not raw capability. If your agent bill is the problem, it's the answer; if quality ceiling is the problem, it isn't.
Full pricing, benchmark table and release notes on the Grok 4.5 page.
UseRightAI recommendations are based on practical decision factors people actually feel in day-to-day use.
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Claude Opus 5 wins on more of the categories we score — coding, research, reasoning — so it is the better default of the two. Grok 4.5 is the better pick when your work is mostly fast and token-efficient coding agents. Neither is universally "better": Claude Opus 5 is aimed at complex agentic coding and enterprise agent workflows, Grok 4.5 at fast and token-efficient coding agents.
Grok 4.5 is cheaper at $2/1M input and $6/1M output. Claude Opus 5 costs $5/1M input and $25/1M output.
Claude Opus 5 has the larger context window at 1M tokens vs Grok 4.5's 500K. For large document analysis, Claude Opus 5 is the stronger pick.
Claude Opus 5 is better for coding with a score of 100 vs Grok 4.5's 94 (out of 100). GPT-6 Astra is the overall coding leader in this directory at 100/100.
Grok 4.5 is faster with a fast speed rating (score: 4) vs Claude Opus 5's deliberate rating (score: 2). Speed matters most for interactive and high-throughput work; for batch jobs the Claude Opus 5 latency penalty is usually invisible.
Still short of Claude Fable 5's absolute frontier ceiling on the hardest long-running agent tasks. Fast mode (research preview) doubles pricing to $10/$50, erasing the cost advantage over Fable 5. Avoid it if you need fast interactive latency (Sonnet 5 is quicker and one-fifth the price) or absolute frontier ceiling (Fable 5). That is the main case for looking at Grok 4.5 instead.
Raw ceiling trails the frontier: 64.7% SWE-bench Pro vs Opus 4.8's 69.2%, with a higher reported hallucination rate. 500K context is half the frontier norm, and rates double at ≥200K prompt tokens. Avoid it if you need the highest solve rate per attempt or verified low hallucination — Claude Opus 5 is the safer premium pick. Against Claude Opus 5 specifically, the gap shows up most on coding (100 vs 94).
Take a moderate workload of 10M input and 2M output tokens a month. Grok 4.5 runs $32.00 (at $2/1M in and $6/1M out); Claude Opus 5 runs $100.00 (at $5/1M in and $25/1M out). That is a $68.00/month difference — Grok 4.5 is the cheaper of the two at this volume, and the gap scales linearly as you send more. Output tokens dominate the bill on both, so prompt length matters far less than response length.
Yes, and for most teams that beats picking one. A common split is Claude Opus 5 for complex agentic coding and enterprise agent workflows, with Grok 4.5 handling fast and token-efficient coding agents. Routing high-volume, low-stakes calls to Grok 4.5 at $2/1M and reserving Claude Opus 5 for the hard cases is usually the cheapest arrangement that does not cost you quality.