Model comparison
Claude Fable 5 vs Mistral Medium 3.5 128B
Head-to-head evidence from 21 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); Mistral Medium 3.5 128B unranked (Not scored). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude Fable 5 and Mistral Medium 3.5 128B share 21 comparable benchmark results. 1 of 8 categories are comparable. 13 results are unique to Claude Fable 5; 4 to Mistral Medium 3.5 128B.
Updated July 23, 2026- Shared results
- 21
- Claude Fable 5 only
- 13
- Mistral Medium 3.5 128B only
- 4
- Comparable categories
- 1 / 8
Treat this as a split decision. Claude Fable 5 makes more sense if coding is the priority or you need the larger 1M+ context window; Mistral Medium 3.5 128B is the better fit if you want the cheaper token bill.
Confidence note. This is a partial-evidence comparison with 21 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 and Mistral Medium 3.5 128B finish on the same BenchAlign overall score, so this is less about a single winner and more about where the edge shows up. The BenchAlign headline says tie; the benchmark table is where the real choice happens.
Claude Fable 5 is also the more expensive model on tokens at $10.00 input / $50.00 output per 1M tokens, versus $1.50 input / $7.50 output per 1M tokens for Mistral Medium 3.5 128B. That is roughly 6.7x on output cost alone. Claude Fable 5 gives you the larger context window at 1M+, compared with 256K for Mistral Medium 3.5 128B.
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 | Mistral Medium 3.5 128B |
|---|---|---|---|
| Coding | Claude Fable 589.2 | Margin← 11.6 | Mistral Medium 3.5 128B77.6 |
| Agentic | Claude Fable 584.6 | MarginNo overlap | Mistral Medium 3.5 128BNot measured |
| Multimodal | Claude Fable 557.9 | MarginNo overlap | Mistral Medium 3.5 128BNot measured |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
SWE-bench Verified
CodingA 95%B 77.6%Winner: Claude Fable 5Δ 17.4SWE-bench Verified: Claude Fable 5 scored 95%; Mistral Medium 3.5 128B scored 77.6%. 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 | Mistral Medium 3.5 128B | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude Fable 5$10 input / $50 output | Mistral Medium 3.5 128B$1.5 input / $7.5 output | Mistral Medium 3.5 128B has the lower combined listed price. |
| Generation speedtokens per second | Claude Fable 5Not available | Mistral Medium 3.5 128BNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude Fable 5Not available | Mistral Medium 3.5 128BNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude Fable 51M+ | Mistral Medium 3.5 128B256K | Claude Fable 5 lists the larger context window. |
Benchmark Deep Dive
Agentic15 benchmarks
| Benchmark | Claude Fable 5 | Mistral Medium 3.5 128B | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | 84.3% | — | Not comparable |
| OSWorld-VerifiedSource | 85% | — | Not comparable |
| GDPval-AASource | 1748 | 929 | Claude Fable 5 leads |
| AA Agentic IndexSource | 52.8% | 19.0% | Claude Fable 5 leads |
| τ²-bench resultsSource | 98.5% | 94.2% | Claude Fable 5 leads |
| GDPval-AASource | 62.4% | 21.4% | Claude Fable 5 leads |
| AA BriefcaseSource | 1574 | 506 | Claude Fable 5 leads |
| AA AutomationBenchSource | 48.6% | — | Not comparable |
| AA EnterpriseOps-GymSource | 51.1% | 33.7% | Claude Fable 5 leads |
| AA Harvey LABSource | 93.6% | 69.1% | Claude Fable 5 leads |
| AA Tau3 BankingSource | 26.8% | 14.4% | Claude Fable 5 leads |
| terminalBenchHardSource | 62.9% | 33.3% | Claude Fable 5 leads |
| aaTerminalBench21Source | 84.6% | — | Not comparable |
| τ³-bench resultsSource | — | 91.4% | Not comparable |
| Gert LabsSource | — | 39.10% | Not comparable |
CodingClaude Fable 5 wins9 benchmarks
| Benchmark | Claude Fable 5 | Mistral Medium 3.5 128B | Result |
|---|---|---|---|
| SWE-bench VerifiedSource | 95% | 77.6% | 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% | 46.9% | Claude Fable 5 leads |
| AA-SciCodeSource | 60.2% | 39.6% | Claude Fable 5 leads |
Reasoning2 benchmarks
Knowledge7 benchmarks
| Benchmark | Claude Fable 5 | Mistral Medium 3.5 128B | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 59.9% | 29.9% | Claude Fable 5 leads |
| AA-GPQA DiamondSource | 92.6% | 74.8% | Claude Fable 5 leads |
| AA-HLESource | 53.3% | 12.8% | Claude Fable 5 leads |
| AA-Omniscience IndexSource | 40.2% | -36.3% | Claude Fable 5 leads |
| AA-Omniscience AccuracySource | 61.4% | 25.1% | Claude Fable 5 leads |
| AA-Omniscience Hallucination RateSource | 54.9% | 82.0% | Claude Fable 5 leads |
| AA Openness IndexSource | — | 33.3% | Not comparable |
Multimodal4 benchmarks
Inst. Following1 benchmarks
| Benchmark | Claude Fable 5 | Mistral Medium 3.5 128B | Result |
|---|---|---|---|
| AA-IFBenchSource | 63.5% | 68.8% | Mistral Medium 3.5 128B leads |
Frequently Asked Questions (2)
Which is better, Claude Fable 5 or Mistral Medium 3.5 128B?
Claude Fable 5 and Mistral Medium 3.5 128B are tied on the BenchAlign overall score, so the right pick depends on which category matters most for your use case.
Which is better for coding, Claude Fable 5 or Mistral Medium 3.5 128B?
Claude Fable 5 has the edge for coding in this comparison, averaging 89.2 versus 77.6. Inside this category, AA Coding Index is the benchmark that creates the most daylight between them.
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