Model comparison
Claude Fable 5 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 Fable 5 #2 (Supported); Grok Code Fast 1 #180 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude Fable 5 and Grok Code Fast 1 share 12 comparable benchmark results. 1 of 8 categories are comparable. 22 results are unique to Claude Fable 5; 0 to Grok Code Fast 1.
Updated July 23, 2026- Shared results
- 12
- Claude Fable 5 only
- 22
- Grok Code Fast 1 only
- 0
- Comparable categories
- 1 / 8
Pick Claude Fable 5 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 Fable 5 is clearly ahead on the BenchAlign aggregate, 83.68 to 38.64. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Claude Fable 5's sharpest advantage is in coding, where it averages 89.2 against 70.8. The single biggest benchmark swing on the page is SWE-bench Verified, 95% to 70.8%.
Claude Fable 5 is also the more expensive model on tokens at $10.00 input / $50.00 output per 1M tokens, versus $0.20 input / $1.50 output per 1M tokens for Grok Code Fast 1. That is roughly 33.3x on output cost alone. Claude Fable 5 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 Fable 5 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 Fable 5 | Δ | Grok Code Fast 1 |
|---|---|---|---|
| Coding | Claude Fable 589.2 | Margin← 18.4 | Grok Code Fast 170.8 |
| Agentic | Claude Fable 584.6 | MarginNo overlap | Grok Code Fast 1Not measured |
| Multimodal | Claude Fable 557.9 | 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 95%B 70.8%Winner: Claude Fable 5Δ 24.2SWE-bench Verified: Claude Fable 5 scored 95%; Grok Code Fast 1 scored 70.8%. Claude Fable 5 wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude Fable 5 | Grok Code Fast 1 | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude Fable 5$10 input / $50 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 Fable 5Not available | Grok Code Fast 1172 tok/s | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude Fable 5Not available | Grok Code Fast 12.81 s | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude Fable 51M+ | Grok Code Fast 1256K | Claude Fable 5 lists the larger context window. |
Benchmark Deep Dive
Agentic13 benchmarks
| Benchmark | Claude Fable 5 | Grok Code Fast 1 | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | 84.3% | — | Not comparable |
| OSWorld-VerifiedSource | 85% | — | Not comparable |
| GDPval-AASource | 1748 | — | Not comparable |
| AA Agentic IndexSource | 52.8% | — | Not comparable |
| τ²-bench resultsSource | 98.5% | 75.7% | Claude Fable 5 leads |
| GDPval-AASource | 62.4% | — | Not comparable |
| AA BriefcaseSource | 1574 | — | Not comparable |
| AA AutomationBenchSource | 48.6% | — | Not comparable |
| AA EnterpriseOps-GymSource | 51.1% | — | Not comparable |
| AA Harvey LABSource | 93.6% | — | Not comparable |
| AA Tau3 BankingSource | 26.8% | — | Not comparable |
| terminalBenchHardSource | 62.9% | — | Not comparable |
| aaTerminalBench21Source | 84.6% | — | Not comparable |
CodingClaude Fable 5 wins9 benchmarks
| Benchmark | Claude Fable 5 | Grok Code Fast 1 | Result |
|---|---|---|---|
| SWE-bench VerifiedSource | 95% | 70.8% | Claude Fable 5 leads |
| SWE-bench ProSource | 80% | — | Not comparable |
| FrontierCode 1.1 MainSource | 53.5% | — | Not comparable |
| Terminal-Bench 2.0Source | 84.3% | — | Not comparable |
| cursorBench31Source | 70.6% | — | Not comparable |
| cursorBench32Source | 70.5% | — | Not comparable |
| VulcanBench v3Source | 87.0% | — | Not comparable |
| AA Coding IndexSource | 76.5% | — | Not comparable |
| AA-SciCodeSource | 60.2% | 36.2% | Claude Fable 5 leads |
Reasoning2 benchmarks
Knowledge6 benchmarks
| Benchmark | Claude Fable 5 | Grok Code Fast 1 | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 59.9% | 21.6% | Claude Fable 5 leads |
| AA-GPQA DiamondSource | 92.6% | 72.7% | Claude Fable 5 leads |
| AA-HLESource | 53.3% | 7.5% | Claude Fable 5 leads |
| AA-Omniscience IndexSource | 40.2% | -36.0% | Claude Fable 5 leads |
| AA-Omniscience AccuracySource | 61.4% | 23.8% | Claude Fable 5 leads |
| AA-Omniscience Hallucination RateSource | 54.9% | 78.5% | Claude Fable 5 leads |
Multimodal3 benchmarks
Inst. Following1 benchmarks
| Benchmark | Claude Fable 5 | Grok Code Fast 1 | Result |
|---|---|---|---|
| AA-IFBenchSource | 63.5% | 41.4% | Claude Fable 5 leads |
Frequently Asked Questions (2)
Which is better, Claude Fable 5 or Grok Code Fast 1?
Claude Fable 5 is ahead on BenchLM's BenchAlign leaderboard, 83.68 to 38.64. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 95% and 70.8%.
Which is better for coding, Claude Fable 5 or Grok Code Fast 1?
Claude Fable 5 has the edge for coding in this comparison, averaging 89.2 versus 70.8. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.
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