Claude Haiku 5.5 vs DeepSeek V4.1 Flash
| Spec | Claude Haiku 5.5 | DeepSeek V4.1 Flash |
|---|---|---|
| Respan Index | 57.2 (#16) | 52.0 (#28) |
| Blended price per 1M | $0.1 | $0.071 |
| Context window | 1M | 1M |
| Input / output per 1M | $0.05 / $0.25 | $0.045 / $0.15 |
| Max output | 128K | 384K |
| Input | text, vision | text, vision |
| Released | 2026-10-07 | 2026-09-10 |
Respan Index by category
Each category is scored 0 to 100, and how far ahead the winner is. Leads under a point are close to even.
| Category | Claude Haiku 5.5 | DeepSeek V4.1 Flash |
|---|---|---|
| Coding | 55.0 Claude Haiku 5.5 | 39.7 DeepSeek V4.1 Flash |
| Agents | 65.9 Claude Haiku 5.5 | 60.0 DeepSeek V4.1 Flash |
| Reasoning | 65.0 Claude Haiku 5.5 | 56.0 DeepSeek V4.1 Flash |
| Knowledge & language | 23.6 Claude Haiku 5.5 | 44.5 DeepSeek V4.1 Flash |
| Human preference | 55.5 Claude Haiku 5.5 | 57.6 DeepSeek V4.1 Flash |
Benchmarks both report
DeepSeek V4.1 Flash leads on 14 of the 22 benchmarks both report. Higher is better. Each score links to where it was published.
| Benchmark | Claude Haiku 5.5 | DeepSeek V4.1 Flash |
|---|---|---|
| SAGE 1.1 (Vals AI) | 89.8% | 85.4% |
| APEX-Agents (Mercor) | 56.1% | 39.5% |
| Chess Puzzles (Epoch AI) | 55% | 48% |
| LMArena Agent (LMArena) | 0.0143 | 0.0267 |
| LMArena Elo | 1425 | 1476 |
| LMArena WebDev (LMArena) | 1589 | 1665 |
| Terminal-Bench 4.0 (Vals AI) | 36.4% | 19.7% |
| FrontierMath Tier 4 v2 (Epoch AI) | 46.3% | 26.8% |
| FrontierMath Tiers 1-3 v2 (Epoch AI) | 75.1% | 67.4% |
| Furniture Assembly (Epoch AI) | 47.5% | 34.2% |
| GPQA Diamond | 89.6% | 90.9% |
| LiveBench Agentic Coding (LiveBench) | 57.2% | 77.3% |
| LiveBench Coding (LiveBench) | 77.9% | 80% |
| LiveBench Data Analysis (LiveBench) | 72.8% | 79.3% |
| LiveBench Instruction Following (LiveBench) | 66.5% | 70% |
| LiveBench Language (LiveBench) | 63.5% | 81.2% |
| LiveBench Mathematics (LiveBench) | 92.8% | 93.3% |
| LiveBench Reasoning (LiveBench) | 84.6% | 86.7% |
| Mystery Game Puzzles (Epoch AI) | 30% | 43% |
| OTIS Mock AIME 2024-2025 (Epoch AI) | 98.9% | 98.3% |
| SAGE (Vals AI) | 45.8% | 47.9% |
| SimpleQA Verified | 23.8% | 42.9% |
FAQ
Is Claude Haiku 5.5 better than DeepSeek V4.1 Flash?
Claude Haiku 5.5 scores 57.2 on the Respan Index (#16), ahead of DeepSeek V4.1 Flash at 52.0 (#28). DeepSeek V4.1 Flash leads on 14 of the 22 benchmarks both report.
Which is cheaper, Claude Haiku 5.5 or DeepSeek V4.1 Flash?
Claude Haiku 5.5 lists at $0.05 input and $0.25 output per 1M tokens; DeepSeek V4.1 Flash at $0.045 and $0.15. DeepSeek V4.1 Flash is 1.4x cheaper per token at list price.
Which has the larger context window?
Both accept 1M tokens of context.