Claude Opus 4.8 vs Grok 4.3
At a Glance
| Compare | Claude Opus 4.8Anthropic | Grok 4.3xAI |
|---|---|---|
| Intelligence, Cost, and Efficiency | ||
| IntelligenceHigher is better · MM Intelligence v2.5 | #18 of 4670.1 score · 3/3 sources · complete | #40 of 4616.6 score · 2/3 sources · provisional · missing ARC-AGI-2 · full-core range 11.1–44.4 |
| CostLower is better · Published-token output estimate | #42 of 44$0.604 per LiveBench case | #7 of 44$0.028 per LiveBench case |
| EfficiencyHigher is better · MM Efficiency v1.5 | #35 of 3840.5 score · 3/3 sources · complete | #33 of 3846.0 score · 2/3 sources · provisional · missing ARC-AGI-2 · full-core range 43.3–59.9 |
| Pricing and Limits | ||
| Input priceFrom · USD / 1M tokens | $5.00Anthropic ↗ · Sep 3, 2026 | $1.25Xai ↗ · Sep 3, 2026 |
| Output priceFrom · USD / 1M tokens | $25.00Anthropic ↗ · Sep 3, 2026 | $2.50Xai ↗ · Sep 3, 2026 |
| Context windowMaximum documented tokens | 1,000K | 1,000K |
| Model facts checked | Aug 29, 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 4.8 | Grok 4.3 |
|---|---|---|
| LMArena Search Arenasearch-2026-08-24-d25aabda0010 · arena_rating · leader | 1,204.30100% of row best · rating · claude-opus-4-8; 95% CI [1197.89112684, 1210.71069451]; votes 70998; rank 12 | 1,164.8097% of row best · rating · grok-4.3; 95% CI [1159.64698972, 1169.95391272]; votes 91483; rank 23 |
| LMArena Text Arenatext-2026-09-13-d25aabda0010 · arena_rating · leader | 1,452.66100% of row best · rating · claude-opus-4-8; 95% CI [1448.52490690, 1456.79817098]; votes 53446; rank 40 | 1,397.7396% of row best · rating · grok-4.3; 95% CI [1394.01930088, 1401.44639527]; votes 66801; rank 145 |
| LMArena Vision Arenavision-2026-09-13-d25aabda0010 · arena_rating · leader | 1,288.23100% of row best · rating · claude-opus-4-8; 95% CI [1281.27991800, 1295.18871241]; votes 15801; rank 25 | 1,229.4795% of row best · rating · grok-4.3; 95% CI [1223.17337452, 1235.75913440]; votes 22688; rank 67 |
| LiveBench2026-06-25 · overall · leader | 81.18100% of row best · percent · claude-opus-4-8-max-effort · 24,171 output tokens / case | 69.2785% of row best · percent · grok-4.3 · 11,184 output tokens / case |
| ToneBench2026-09-11-10-task-4ef099199c9c · overall_score · unverified | 87.91100% of row best · points · Claude Opus 4.8 (max effort) · 24,846 output tokens / case | 74.9185% of row best · points · Grok 4.3 (high) · 5,154 output tokens / case |
| Overall ResultCounted from the protocol-matched rows above | 4 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 4.8 | Grok 4.3 |
|---|---|---|
| Developer | Anthropic | xAI |
| Family | Claude 4 8 | Grok 4 |
| Model | Claude Opus 4.8 | Grok 4.3 |
| Version | Claude Opus 4.8 | Grok 4.3 |
| Lifecycle | active | active |
| Released | 2026-05-28 | 2026-06-17 |
| Knowledge cutoff | 2026-01-01 | Unknown |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |
| Context window | 1,000K | 1,000K |
| 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) | Xai (Standard) |
| Capabilities | chat, generation, reasoning, tools | chat, generation, reasoning, structured_outputs, tools |
Claude Opus 4.8 Capabilities
Grok 4.3 Capabilities
Related Comparisons
All image comparisons →| A | Pair | B | Context |
|---|---|---|---|
Claude Opus 4.8Anthropic | vs |  GPT-6 AstraOpenAI | cross-developer peersimage, text |
Claude Fable 5.1Anthropic | vs | Claude Opus 4.8Anthropic | family variantsimage, text |
Claude Opus 4.8Anthropic | vs |  Gemini 3.1 ProGoogle DeepMind | cross-developer peerstext |
Claude Opus 4.8Anthropic | vs |  DeepSeek-V4.1-FlashDeepSeek | cross-developer peersimage, text |
Claude Opus 4.8Anthropic | vs | Grok 4.6xAI | cross-developer peersimage, text |
Claude Opus 4.8Anthropic | vs |  Qwen3.8-MaxQwen | cross-developer peersimage, text |
Claude Opus 4.8Anthropic | vs |  Kimi-K3Moonshot AI | cross-developer peersimage, text |
 MiniMax-M3MiniMax | vs | Claude Opus 4.8Anthropic | cross-developer peersimage, text |
Claude Opus 4.8Anthropic | vs |  GLM-5.3Z.ai | cross-developer peerstext |
Claude Opus 4.8Anthropic | vs |  Hy4 previewTencent | cross-developer peerstext |
Claude Opus 4.8Anthropic | vs | Seed 2.1 ProByteDance Seed | cross-developer peersimage, text |
Claude Opus 4.8Anthropic | vs |  Mistral Large 3Mistral AI | cross-developer peersimage, text |
Primary Evidence
Sources and Freshness
Questions
Claude Opus 4.8 vs Grok 4.3 FAQs
Is Claude Opus 4.8 or Grok 4.3 better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both Claude Opus 4.8 and Grok 4.3, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, Claude Opus 4.8 or Grok 4.3?+
Claude Opus 4.8 is $5.00 and Grok 4.3 is $1.25 per million tokens, so Grok 4.3 is cheaper on this metric. Claude Opus 4.8 is $25.00 and Grok 4.3 is $2.50 per million tokens, so Grok 4.3 is cheaper on this metric.
Which has a larger context window, Claude Opus 4.8 or Grok 4.3?+
Neither model has a larger sourced context window in this comparison. Claude Opus 4.8 is 1,000K and Grok 4.3 is 1,000K.
Which performs better in benchmarks, Claude Opus 4.8 or Grok 4.3?+
Claude Opus 4.8 leads the current overall benchmark count. The result uses 4 protocol-matched benchmarks from 2 publishers; it is not a universal quality score.
Can Claude Opus 4.8 or Grok 4.3 be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. Claude Opus 4.8 is not marked open weight; Grok 4.3 is not marked open weight.
Can Claude Opus 4.8 and Grok 4.3 understand images?+
Claude Opus 4.8 is documented with image input; Grok 4.3 is documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, Claude Opus 4.8 or Grok 4.3?+
Neither has a larger sourced maximum output. Claude Opus 4.8 is 128K and Grok 4.3 is —.
Do Claude Opus 4.8 and Grok 4.3 support reasoning and tool use?+
Claude Opus 4.8: reasoning, tool calling, and image input. Grok 4.3: reasoning, tool calling, and image input. Feature support does not establish relative quality.
Which is available from more inference providers, Claude Opus 4.8 or Grok 4.3?+
Claude Opus 4.8 has 2 sourced provider routes; Grok 4.3 has 1, so Claude Opus 4.8 has broader tracked availability.
Which offers better value, Claude Opus 4.8 or Grok 4.3?+
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.