Claude Haiku 5.5 vs Mercury 2.5
Claude Haiku 5.5 comes out ahead, 76 to 55 on our weighted score, and it is the cheaper option too.
- Our pick
AnthropicClaude Haiku 5.5
76/100- ECI160.4
- Price$0.10 / $0.50
- Context1M
InceptionMercury 2.5
55/100- ECI—
- Price$0.20 / $0.75
- Context260K
Add a model
Make it a three-way comparison.
Claude Haiku 5.5 is our pick
Claude Haiku 5.5 is the better all-round choice, scoring 76/100 against Mercury 2.5 (55). It leads on price, inputs & features and context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
- CapabilityNot enough dataNo independent benchmark covers every model here yet
- Lowest priceClaude Haiku 5.5Claude Haiku 5.5 $0.20 · Mercury 2.5 $0.338 per 1M tokens (3:1 blend)
- Longest contextClaude Haiku 5.5Claude Haiku 5.5 1,000,000 · Mercury 2.5 260,000 tokens
- Widest inputsClaude Haiku 5.5Claude Haiku 5.5: Text, Images, PDFs · Mercury 2.5: Text
- Self-hostingNo open weightsBoth are available only through APIs
| Measure | Weight | Claude Haiku 5.5 | Mercury 2.5 |
|---|---|---|---|
| Price | 50% | 80 | 69 |
| Inputs & features | 30% | 80 | 45 |
| Context window | 20% | 60 | 36 |
| Overall | 100% | 76/100 | 55/100 |
Left out because at least one model lacks the data: capability. The remaining weights were rescaled.
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Claude Haiku 5.5Anthropic | Mercury 2.5Inception |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | 160.4 | — |
| ECI rank | #14 of 165 | — |
| GPQA DiamondGraduate-level science questions | 89.7% | — |
| FrontierMath Tiers 1–3Research-level mathematics | 75.1% | — |
| OTIS Mock AIME 2024–2025Competition mathematics | 98.9% | — |
| SimpleQA VerifiedShort factual questions | 23.8% | — |
| Price per million tokens | ||
| Input | $0.10 (best) | $0.20 |
| Output | $0.50 (best) | $0.75 |
| Cached input | $0.01 (best) | $0.02 |
| Blended (3:1) | $0.20 (best) | $0.338 |
| Long-context rate | Over 100K: $0.50 / $2.50 | Same rate |
| Price source | Official Anthropic API | Official Inception API |
| Limits | ||
| Context window | 1,000,000 tokens (best) | 260,000 tokens |
| Max output | 128,000 tokens (best) | 65,536 tokens |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | No |
| PDFs | Yes | No |
| Audio | No | No |
| Video | No | No |
| Reasoning | Yeslow · medium · high · xhigh · max | Yeslow · medium · high |
| Tool calling | Yes | Yes |
| Structured output | Yes | Yes |
| Availability | ||
| Weights | Proprietary | Proprietary |
| API model ID | claude-haiku-5-5 | mercury-2.5 |
| API providers | 33 (best) | 6 |
| Released | Oct 7, 2026 | Sep 8, 2026 |
| Knowledge cutoff | Jun 2026 | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Claude Haiku 5.5$2.00
- Mercury 2.5$3.50
Which should you choose?
Which is better: Claude Haiku 5.5 or Mercury 2.5?
Claude Haiku 5.5 is the better all-round choice, scoring 76/100 against Mercury 2.5 (55). It leads on price, inputs & features and context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
Which is cheaper, Claude Haiku 5.5 or Mercury 2.5?
Claude Haiku 5.5 is cheaper at $0.10 input / $0.50 output per million tokens (official Anthropic API price). Mercury 2.5 costs $0.20 input / $0.75 output per million tokens (official Inception API price). At a typical mix of three input tokens to one output token, that is $0.20 per million tokens for Claude Haiku 5.5 versus $0.338 for Mercury 2.5 (1.7× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers both models yet. Claude Haiku 5.5 has an ECI of 160.4 and Mercury 2.5 has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Claude Haiku 5.5 and Mercury 2.5 yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.
Which has the bigger context window?
Claude Haiku 5.5 has the largest context window at 1,000,000 tokens, against 260,000 for Mercury 2.5. Maximum output per response: Claude Haiku 5.5 up to 128,000, Mercury 2.5 up to 65,536 tokens.
Which can read images, PDFs, audio or video?
Claude Haiku 5.5 accepts text, images and PDFs; Mercury 2.5 accepts text. Claude Haiku 5.5 handles the widest range of inputs.
Are any of these open source?
No. Claude Haiku 5.5 and Mercury 2.5 are proprietary and only available through APIs and apps.
Which is newer?
Claude Haiku 5.5 is the newest, released Oct 7, 2026. Mercury 2.5 came out Sep 8, 2026. Knowledge cutoff: Claude Haiku 5.5 Jun 2026.
How do you decide the winner?
Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Nov 2, 2026.
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