Model comparison
Claude 3.5 Sonnet vs Step 3.7 Flash
Head-to-head evidence from 0 shared benchmark results across 0 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Claude 3.5 Sonnet #132 (Estimated); Step 3.7 Flash #110 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude 3.5 Sonnet and Step 3.7 Flash share 0 comparable benchmark results. 1 of 8 categories are comparable. 4 results are unique to Claude 3.5 Sonnet; 29 to Step 3.7 Flash.
Updated July 21, 2026- Shared results
- 0
- Claude 3.5 Sonnet only
- 4
- Step 3.7 Flash only
- 29
- Comparable categories
- 1 / 8
Pick Step 3.7 Flash if you want the stronger benchmark profile. Claude 3.5 Sonnet only becomes the better choice if you would rather avoid the extra latency and token burn of a reasoning model.
Confidence note. This is a partial-evidence comparison with 0 shared benchmark results across 0 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
Step 3.7 Flash is clearly ahead on the BenchAlign aggregate, 50.87 to 47.74. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Step 3.7 Flash's sharpest advantage is in coding, where it averages 56.3 against 49.
Claude 3.5 Sonnet is also the more expensive model on tokens at $3.00 input / $15.00 output per 1M tokens, versus $0.20 input / $1.15 output per 1M tokens for Step 3.7 Flash. That is roughly 13.0x on output cost alone. Step 3.7 Flash is the reasoning model in the pair, while Claude 3.5 Sonnet 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. Step 3.7 Flash gives you the larger context window at 256K, compared with 200K for Claude 3.5 Sonnet.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude 3.5 Sonnet | Step 3.7 Flash | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude 3.5 Sonnet$3 input / $15 output | Step 3.7 Flash$0.2 input / $1.15 output | Step 3.7 Flash has the lower combined listed price. |
| Generation speedtokens per second | Claude 3.5 SonnetNot available | Step 3.7 FlashNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude 3.5 SonnetNot available | Step 3.7 FlashNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude 3.5 Sonnet200K | Step 3.7 Flash256K | Step 3.7 Flash lists the larger context window. |
Benchmark Deep Dive
Agentic12 benchmarks
| Benchmark | Claude 3.5 Sonnet | Step 3.7 Flash | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | — | 59.5% | Not comparable |
| BrowseCompSource | — | 75.8% | Not comparable |
| DeepSearchQASource | — | 92.8% | Not comparable |
| GDPval-AASource | — | 25.9% | Not comparable |
| ToolathlonSource | — | 49.5% | Not comparable |
| Claw-EvalSource | — | 67.1% | Not comparable |
| HLE w/ toolsSource | — | 47.2% | Not comparable |
| Gert LabsSource | — | 51.57% | Not comparable |
| AA Agentic IndexSource | — | 21.5% | Not comparable |
| τ²-bench resultsSource | — | 98.5% | Not comparable |
| GDPval-AASource | — | 1017 | Not comparable |
| APEX-Agents-AASource | — | 14.8% | Not comparable |
CodingStep 3.7 Flash wins5 benchmarks
Reasoning2 benchmarks
Knowledge7 benchmarks
| Benchmark | Claude 3.5 Sonnet | Step 3.7 Flash | Result |
|---|---|---|---|
| GPQASource | 59.4% | — | Not comparable |
| Artificial Analysis Intelligence IndexSource | — | 30.3% | Not comparable |
| AA-GPQA DiamondSource | — | 80.9% | Not comparable |
| AA-HLESource | — | 19.9% | Not comparable |
| AA-Omniscience IndexSource | — | -37.5% | Not comparable |
| AA-Omniscience AccuracySource | — | 25.4% | Not comparable |
| AA-Omniscience Hallucination RateSource | — | 84.4% | Not comparable |
Math2 benchmarks
Multimodal4 benchmarks
Inst. Following1 benchmarks
| Benchmark | Claude 3.5 Sonnet | Step 3.7 Flash | Result |
|---|---|---|---|
| AA-IFBenchSource | — | 67.3% | Not comparable |
Frequently Asked Questions (2)
Which is better, Claude 3.5 Sonnet or Step 3.7 Flash?
Step 3.7 Flash is ahead on BenchLM's BenchAlign leaderboard, 50.87 to 47.74.
Which is better for coding, Claude 3.5 Sonnet or Step 3.7 Flash?
Step 3.7 Flash has the edge for coding in this comparison, averaging 56.3 versus 49. Claude 3.5 Sonnet stays close enough that the answer can still flip depending on your workload.
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