Claude Opus 5 vs Grok 4.5
At a Glance
| Compare | Claude Opus 5Anthropic | Grok 4.5xAI |
|---|---|---|
| Intelligence, Cost, and Efficiency | ||
| IntelligenceHigher is better · MM Intelligence v2.5 | #3 of 4694.1 score · 3/3 sources · complete | #25 of 4660.1 score · 3/3 sources · complete |
| CostLower is better · Published-token output estimate | #39 of 44$0.371 per LiveBench case | #15 of 44$0.063 per LiveBench case |
| EfficiencyHigher is better · MM Efficiency v1.5 | #13 of 3857.6 score · 3/3 sources · complete | #11 of 3859.2 score · 3/3 sources · complete |
| Pricing and Limits | ||
| Input priceFrom · USD / 1M tokens | $5.00Anthropic ↗ · Sep 3, 2026 | $2.00Xai ↗ · Sep 3, 2026 |
| Output priceFrom · USD / 1M tokens | $25.00Anthropic ↗ · Sep 3, 2026 | $6.00Xai ↗ · Sep 3, 2026 |
| Context windowMaximum documented tokens | 1,000K | 500K |
| Model facts checked | Aug 28, 2026View model evidence → | Sep 3, 2026View model evidence → |
Token prices are the lowest available sourced USD rates; input and output may use different providers. Cost ranking estimates output spend on LiveBench, not a full request bill. Ranking methodology →
Available Benchmarks
| Benchmark | Claude Opus 5 | Grok 4.5 |
|---|---|---|
| ARC-AGI-1verified-v1-ba05d69f6453 · verified_score · leader | 97.50100% of row best · percent · Claude Opus 5 (Max) | 87.1789% of row best · percent · Grok 4.5 (Medium) |
| ARC-AGI-2verified-v2-6c676fa3e9af · verified_score · leader | 90.42100% of row best · percent · Claude Opus 5 (Max) | 52.6458% of row best · percent · Grok 4.5 (Medium) |
| LMArena Agent Arenaagent-2026-09-15-d25aabda0010 · outcome_score · leader | 10.16100% of row best · score · Claude Opus 5 (Max); 95% CI [8.61078356, 11.71492901]; sessions 19934; observations 2534849; rank 4 | 2.9293% of row best · score · Grok 4.5; 95% CI [1.93207740, 3.90928463]; sessions 38146; observations 1942877; rank 19 |
| LMArena Document Arenadocument-2026-09-13-d25aabda0010 · arena_rating · leader | 1,516.27100% of row best · rating · claude-opus-5-high; 95% CI [1509.24512533, 1523.28765667]; votes 8794; rank 1 | 1,451.9696% of row best · rating · grok-4.5; 95% CI [1443.26182849, 1460.65626012]; votes 4965; rank 26 |
| LMArena Text Arenatext-2026-09-13-d25aabda0010 · arena_rating · leader | 1,504.92100% of row best · rating · claude-opus-5-high; 95% CI [1500.70174969, 1509.13092375]; votes 42617; rank 3 | 1,450.1396% of row best · rating · grok-4.5; 95% CI [1445.44268767, 1454.81726995]; votes 30103; rank 45 |
| LMArena Vision Arenavision-2026-09-13-d25aabda0010 · arena_rating · leader | 1,321.21100% of row best · rating · claude-opus-5-high; 95% CI [1313.68410123, 1328.73941303]; votes 11599; rank 3 | 1,288.5498% of row best · rating · grok-4.5; 95% CI [1280.47745270, 1296.60872281]; votes 8355; rank 24 |
| LiveBench2026-06-25 · overall · leader | 83.44100% of row best · percent · claude-opus-5-max-effort · 14,826 output tokens / case | 80.0196% of row best · percent · grok-4.5 · 10,517 output tokens / case |
| ToneBench2026-09-11-10-task-4ef099199c9c · overall_score · unverified | 88.76100% of row best · points · Claude Opus 5 (max effort) · 9,446 output tokens / case | 82.2393% of row best · points · Grok 4.5 · 2,688 output tokens / case |
| Overall ResultCounted from the protocol-matched rows above | 7 benchmark winsOverall lead | 0 benchmark wins |
Third-party benchmark Only like-for-like primary-publisher results are shown; raw scores, relative scores, configuration, and token spend remain visible.
Side-by-Side Facts
| Field | Claude Opus 5 | Grok 4.5 |
|---|---|---|
| Developer | Anthropic | xAI |
| Family | Claude 5 | Grok 4 |
| Model | Claude Opus 5 | Grok 4.5 |
| Version | Claude Opus 5 | Grok 4.5 |
| Lifecycle | active | active |
| Released | 2026-07-24 | 2026-07-16 |
| Knowledge cutoff | Unknown | Unknown |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |
| Context window | 1,000K | 500K |
| Total parameters | Unknown | Unknown |
| Active parameters | Unknown | Unknown |
| License | Unknown | Unknown |
| Open weights | No | No |
| API available | Yes | Yes |
| Self-hostable | No | No |
| Provider access | Anthropic (Standard), Deepinfra (Standard), Openrouter (Standard) | Xai (Standard) |
| Capabilities | chat, generation, reasoning, tools | chat, generation, reasoning, structured_outputs, tools |
Claude Opus 5 Capabilities
Grok 4.5 Capabilities
Related Comparisons
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|---|---|---|---|
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Claude Fable 5.1Anthropic | vs | Claude Opus 5Anthropic | family variantsimage, text |
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Claude Opus 5Anthropic | vs |  DeepSeek-V4.1-FlashDeepSeek | cross-developer peersimage, text |
Claude Opus 5Anthropic | vs | Grok 4.6xAI | cross-developer peersimage, text |
Claude Opus 5Anthropic | vs |  Qwen3.8-MaxQwen | cross-developer peersimage, text |
Claude Opus 5Anthropic | vs |  Kimi-K3Moonshot AI | cross-developer peersimage, text |
 MiniMax-M3MiniMax | vs | Claude Opus 5Anthropic | cross-developer peersimage, text |
Claude Opus 5Anthropic | vs |  GLM-5.3Z.ai | cross-developer peerstext |
Claude Opus 5Anthropic | vs |  Hy4 previewTencent | cross-developer peerstext |
Claude Opus 5Anthropic | vs | Seed 2.1 ProByteDance Seed | cross-developer peersimage, text |
Primary Evidence
Sources and Freshness
Questions
Claude Opus 5 vs Grok 4.5 FAQs
Is Claude Opus 5 or Grok 4.5 better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both Claude Opus 5 and Grok 4.5, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, Claude Opus 5 or Grok 4.5?+
Claude Opus 5 is $5.00 and Grok 4.5 is $2.00 per million tokens, so Grok 4.5 is cheaper on this metric. Claude Opus 5 is $25.00 and Grok 4.5 is $6.00 per million tokens, so Grok 4.5 is cheaper on this metric.
Which has a larger context window, Claude Opus 5 or Grok 4.5?+
Claude Opus 5 has the larger sourced context window. Claude Opus 5 supports 1,000K and Grok 4.5 supports 500K.
Which performs better in benchmarks, Claude Opus 5 or Grok 4.5?+
Claude Opus 5 leads the current overall benchmark count. The result uses 7 protocol-matched benchmarks from 3 publishers; it is not a universal quality score.
Can Claude Opus 5 or Grok 4.5 be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. Claude Opus 5 is not marked open weight; Grok 4.5 is not marked open weight.
Can Claude Opus 5 and Grok 4.5 understand images?+
Claude Opus 5 is documented with image input; Grok 4.5 is documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, Claude Opus 5 or Grok 4.5?+
Neither has a larger sourced maximum output. Claude Opus 5 is 128K and Grok 4.5 is —.
Do Claude Opus 5 and Grok 4.5 support reasoning and tool use?+
Claude Opus 5: reasoning, tool calling, and image input. Grok 4.5: reasoning, tool calling, and image input. Feature support does not establish relative quality.
Which is available from more inference providers, Claude Opus 5 or Grok 4.5?+
Claude Opus 5 has 3 sourced provider routes; Grok 4.5 has 1, so Claude Opus 5 has broader tracked availability.
Which offers better value, Claude Opus 5 or Grok 4.5?+
There is no universal value winner. Compare the input and output prices above with the matched benchmark result for your workload: cheaper tokens can be offset by different quality, token usage, latency, or provider availability.