In short
How they differ.
Worked out from the figures below. Prices and specs are the makers' own, read Oct 20, 2026.
- Claude Haiku 5.5 is cheaper per output token: $0.50 against $10 per million tokens, so Claude Sonnet 5.5 costs 20 times as much.
- On the 6 independent boards that rank both, Claude Sonnet 5.5 places higher on 6 and Claude Haiku 5.5 on 0.
Side by side
The specs.
| Claude Haiku 5.5 | Claude Sonnet 5.5 | |
|---|---|---|
| Made by | Anthropic · US | Anthropic · US |
| Released | Oct 7, 2026 | Sep 28, 2026 |
| Price per 1M tokens | $0.10 in / $0.50 out | $2 in / $10 out |
| Context window | 1M | 1M |
| Takes in | text, image | text, image |
| Download and run it yourself | No | No |
| Size | Not published | Not published |
| Maker says | “For high-volume, latency-sensitive tasks such as classification, extraction, and routing” | “High-performance model for coding and agents” |
| Sources | Prices, Oct 20, 2026 · Description | Prices, Oct 20, 2026 · Description |
Independent tests
Where they place.
Position on each board we follow (1 is best). Epoch AI's and Vectara's scores are shown; the other boards are linked for their own figures.
| Board | Claude Haiku 5.5 | Claude Sonnet 5.5 |
|---|---|---|
| Epoch Capabilities IndexEpoch AI, Oct 20, 2026 | #14158.98 | #6164.45 |
| LMArena WebDevLMArena, Oct 19, 2026 | Not listed | #3 |
| LMArena mathLMArena, Oct 15, 2026 | Not listed | #15 |
| LMArena Agent ArenaLMArena, Oct 19, 2026 | Not listed | #5 |
| Humanity's Last ExamScale AI | Not listed | #6 |
| SWE-Bench ProScale AI, Sep 22, 2026 | #16 | #8 |
| MultiChallengeScale AI, Feb 3, 2026 | #6 | Not listed |
| Vals IndexVals AI, Oct 19, 2026 | #10 | #1 |
| Terminal-Bench 4.0Vals AI, Oct 19, 2026 | #15 | #2 |
| Vibe Code BenchVals AI, Oct 18, 2026 | #3 | #1 |
| ProofBenchVals AI, Oct 12, 2026 | #11 | #1 |
More comparisons