Model comparison
Claude Opus 4.8 vs Grok Code Fast 1
Head-to-head evidence from 12 shared benchmark results across 5 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Claude Opus 4.8 #5 (Supported); Grok Code Fast 1 #180 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude Opus 4.8 and Grok Code Fast 1 share 12 comparable benchmark results. 1 of 8 categories are comparable. 41 results are unique to Claude Opus 4.8; 0 to Grok Code Fast 1.
Updated July 23, 2026- Shared results
- 12
- Claude Opus 4.8 only
- 41
- Grok Code Fast 1 only
- 0
- Comparable categories
- 1 / 8
Pick Claude Opus 4.8 if you want the stronger benchmark profile. Grok Code Fast 1 only becomes the better choice if you want the cheaper token bill or you would rather avoid the extra latency and token burn of a reasoning model.
Confidence note. This is a partial-evidence comparison with 12 shared benchmark results across 5 evidence categories; 1 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
Claude Opus 4.8 is clearly ahead on the BenchAlign aggregate, 78.34 to 38.64. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Claude Opus 4.8's sharpest advantage is in coding, where it averages 81.1 against 70.8. The single biggest benchmark swing on the page is SWE-bench Verified, 88.6% to 70.8%.
Claude Opus 4.8 is also the more expensive model on tokens at $5.00 input / $25.00 output per 1M tokens, versus $0.20 input / $1.50 output per 1M tokens for Grok Code Fast 1. That is roughly 16.7x on output cost alone. Claude Opus 4.8 is the reasoning model in the pair, while Grok Code Fast 1 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. Claude Opus 4.8 gives you the larger context window at 1M, compared with 256K for Grok Code Fast 1.
Category breakdown
Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.
| Category | Claude Opus 4.8 | Δ | Grok Code Fast 1 |
|---|---|---|---|
| Coding | Claude Opus 4.881.1 | Margin← 10.3 | Grok Code Fast 170.8 |
| Agentic | Claude Opus 4.880.3 | MarginNo overlap | Grok Code Fast 1Not measured |
| Knowledge | Claude Opus 4.862.7 | MarginNo overlap | Grok Code Fast 1Not measured |
| Math | Claude Opus 4.853.9 | MarginNo overlap | Grok Code Fast 1Not measured |
| Multimodal | Claude Opus 4.877.0 | MarginNo overlap | Grok Code Fast 1Not measured |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
SWE-bench Verified
CodingA 88.6%B 70.8%Winner: Claude Opus 4.8Δ 17.8SWE-bench Verified: Claude Opus 4.8 scored 88.6%; Grok Code Fast 1 scored 70.8%. Claude Opus 4.8 wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude Opus 4.8 | Grok Code Fast 1 | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude Opus 4.8$5 input / $25 output | Grok Code Fast 1$0.2 input / $1.5 output | Grok Code Fast 1 has the lower combined listed price. |
| Generation speedtokens per second | Claude Opus 4.8Not available | Grok Code Fast 1172 tok/s | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude Opus 4.8Not available | Grok Code Fast 12.81 s | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude Opus 4.81M | Grok Code Fast 1256K | Claude Opus 4.8 lists the larger context window. |
Benchmark Deep Dive
Agentic21 benchmarks
| Benchmark | Claude Opus 4.8 | Grok Code Fast 1 | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | 74.6% | — | Not comparable |
| BrowseCompSource | 84.3% | — | Not comparable |
| DeepSearchQASource | 93.1% | — | Not comparable |
| OSWorld-VerifiedSource | 83.4% | — | Not comparable |
| Finance Agent v2Source | 53.9% | — | Not comparable |
| GDPval-AASource | 1594 | — | Not comparable |
| MCP AtlasSource | 82.2% | — | Not comparable |
| ToolathlonSource | 59.9% | — | Not comparable |
| Gert LabsSource | 72.97% | — | Not comparable |
| AA Agentic IndexSource | 47.2% | — | Not comparable |
| τ²-bench resultsSource | 94.4% | 75.7% | Claude Opus 4.8 leads |
| GDPval-AASource | 54.7% | — | Not comparable |
| ResearchClawBenchSource | 21.1% | — | Not comparable |
| OSWorld 2.0Source | 20.6% | — | Not comparable |
| AA BriefcaseSource | 1347 | — | Not comparable |
| AA AutomationBenchSource | 48.5% | — | Not comparable |
| AA EnterpriseOps-GymSource | 44.0% | — | Not comparable |
| AA Harvey LABSource | 91.1% | — | Not comparable |
| AA Tau3 BankingSource | 27.6% | — | Not comparable |
| terminalBenchHardSource | 58.3% | — | Not comparable |
| aaTerminalBench21Source | 84.6% | — | Not comparable |
CodingClaude Opus 4.8 wins10 benchmarks
| Benchmark | Claude Opus 4.8 | Grok Code Fast 1 | Result |
|---|---|---|---|
| SWE-bench VerifiedSource | 88.6% | 70.8% | Claude Opus 4.8 leads |
| SWE-bench ProSource | 69.2% | — | Not comparable |
| SWE MultilingualSource | 84.4% | — | Not comparable |
| SWE MultimodalSource | 38.4% | — | Not comparable |
| Terminal-Bench 2.0Source | 74.6% | — | Not comparable |
| cursorBench31Source | 58.4% | — | Not comparable |
| cursorBench32Source | 62.3% | — | Not comparable |
| AA Coding IndexSource | 74.3% | — | Not comparable |
| AA-SciCodeSource | 53.5% | 36.2% | Claude Opus 4.8 leads |
| FrontierCode 1.1 MainSource | 46.5% | — | Not comparable |
Reasoning2 benchmarks
Knowledge10 benchmarks
| Benchmark | Claude Opus 4.8 | Grok Code Fast 1 | Result |
|---|---|---|---|
| GPQASource | 93.6% | — | Not comparable |
| GPQA-DSource | 93.6% | — | Not comparable |
| HLESource | 57.9% | — | Not comparable |
| HLE w/o toolsSource | 49.8% | — | Not comparable |
| Artificial Analysis Intelligence IndexSource | 55.7% | 21.6% | Claude Opus 4.8 leads |
| AA-GPQA DiamondSource | 92.0% | 72.7% | Claude Opus 4.8 leads |
| AA-HLESource | 45.7% | 7.5% | Claude Opus 4.8 leads |
| AA-Omniscience IndexSource | 27.4% | -36.0% | Claude Opus 4.8 leads |
| AA-Omniscience AccuracySource | 46.6% | 23.8% | Claude Opus 4.8 leads |
| AA-Omniscience Hallucination RateSource | 35.9% | 78.5% | Claude Opus 4.8 leads |
Math3 benchmarks
Multilingual1 benchmarks
| Benchmark | Claude Opus 4.8 | Grok Code Fast 1 | Result |
|---|---|---|---|
| INCLUDESource | 87.6% | — | Not comparable |
Multimodal5 benchmarks
Inst. Following1 benchmarks
| Benchmark | Claude Opus 4.8 | Grok Code Fast 1 | Result |
|---|---|---|---|
| AA-IFBenchSource | 62.2% | 41.4% | Claude Opus 4.8 leads |
Frequently Asked Questions (2)
Which is better, Claude Opus 4.8 or Grok Code Fast 1?
Claude Opus 4.8 is ahead on BenchLM's BenchAlign leaderboard, 78.34 to 38.64. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 88.6% and 70.8%.
Which is better for coding, Claude Opus 4.8 or Grok Code Fast 1?
Claude Opus 4.8 has the edge for coding in this comparison, averaging 81.1 versus 70.8. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.
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