Model comparison
Claude Fable 5 vs LFM2.5-8B-A1B
Head-to-head evidence from 11 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); LFM2.5-8B-A1B #166 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude Fable 5 and LFM2.5-8B-A1B share 11 comparable benchmark results. 0 of 8 categories are comparable. 23 results are unique to Claude Fable 5; 6 to LFM2.5-8B-A1B.
Updated July 23, 2026- Shared results
- 11
- Claude Fable 5 only
- 23
- LFM2.5-8B-A1B only
- 6
- Comparable categories
- 0 / 8
Benchmark data for Claude Fable 5 and LFM2.5-8B-A1B is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 11 shared benchmark results across 5 evidence categories; 0 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
BenchLM has partial data for these models, but not enough overlapping benchmark coverage to produce a fair score-level comparison yet.
Claude Fable 5 is priced at $10.00 input / $50.00 output per 1M tokens, versus $0.00 input / $0.00 output per 1M tokens for LFM2.5-8B-A1B. Claude Fable 5 has the larger context window at 1M+, compared with 128K for LFM2.5-8B-A1B.
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 | LFM2.5-8B-A1B |
|---|---|---|---|
| Agentic | Claude Fable 584.6 | MarginNo overlap | LFM2.5-8B-A1BNot measured |
| Coding | Claude Fable 589.2 | MarginNo overlap | LFM2.5-8B-A1BNot measured |
| Math | Claude Fable 5Not measured | MarginNo overlap | LFM2.5-8B-A1B50.0 |
| Multimodal | Claude Fable 557.9 | MarginNo overlap | LFM2.5-8B-A1BNot measured |
| Inst. Following | Claude Fable 5Not measured | MarginNo overlap | LFM2.5-8B-A1B68.8 |
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude Fable 5 | LFM2.5-8B-A1B | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude Fable 5$10 input / $50 output | LFM2.5-8B-A1B$0 input / $0 output | LFM2.5-8B-A1B has the lower combined listed price. |
| Generation speedtokens per second | Claude Fable 5Not available | LFM2.5-8B-A1BNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude Fable 5Not available | LFM2.5-8B-A1BNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude Fable 51M+ | LFM2.5-8B-A1B128K | Claude Fable 5 lists the larger context window. |
Benchmark Deep Dive
Agentic14 benchmarks
| Benchmark | Claude Fable 5 | LFM2.5-8B-A1B | 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% | 16.1% | 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 |
| BFCL v4Source | — | 49.7% | Not comparable |
Coding9 benchmarks
| Benchmark | Claude Fable 5 | LFM2.5-8B-A1B | Result |
|---|---|---|---|
| SWE-bench VerifiedSource | 95% | — | Not comparable |
| 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% | 7.8% | Claude Fable 5 leads |
Reasoning2 benchmarks
Knowledge6 benchmarks
| Benchmark | Claude Fable 5 | LFM2.5-8B-A1B | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 59.9% | 8.3% | Claude Fable 5 leads |
| AA-GPQA DiamondSource | 92.6% | 51.3% | Claude Fable 5 leads |
| AA-HLESource | 53.3% | 6.9% | Claude Fable 5 leads |
| AA-Omniscience IndexSource | 40.2% | -33.3% | Claude Fable 5 leads |
| AA-Omniscience AccuracySource | 61.4% | 9.4% | Claude Fable 5 leads |
| AA-Omniscience Hallucination RateSource | 54.9% | 47.0% | LFM2.5-8B-A1B leads |
Math3 benchmarks
Multimodal3 benchmarks
Frequently Asked Questions (3)
Can I compare Claude Fable 5 and LFM2.5-8B-A1B on BenchLM yet?
Not fully yet. BenchLM is tracking both models, but the sourced benchmark breakdown for this comparison is still coming soon.
Why does this comparison show “coming soon”?
BenchLM only shows category winners and benchmark-level calls when we have sourced results that can be compared fairly. For these models, the public benchmark coverage is not complete enough yet.
What data is available for Claude Fable 5 and LFM2.5-8B-A1B today?
Claude Fable 5: $10.00 input / $50.00 output per 1M tokens LFM2.5-8B-A1B: $0.00 input / $0.00 output per 1M tokens Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.
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