Model comparisons
Claude Haiku 5.5 bills 28% less than Mercury 3 per million output tokens. Tier prices, request fields and limits side by side.
Claude Haiku 5.5 is designed for high-volume, cost-sensitive work such as summaries, classification and database queries. The Haiku 5.5 endpoint here accepts 100,000 input tokens and supports streaming, image input and function calls for short operational workflows.
View model details →View sample outputs →Mercury 3 from Inception supports responsive text reasoning and agent interactions. This chat API accepts text, provides a 1,000,000-token input budget and accepts max_tokens up to 131,072. Stream Mercury 3’s text as it arrives, or let a function-call result supply the evidence for the next step in fast text turns with Mercury 3.
View model details →View sample outputs →Compare
Start with the input you have, the result you want and your budget. These are the differences that affect that choice.
Compare the published examples, then try the same input on both models with matching settings.
The Spicy Index and Freedom Score for both models, from the same daily calculation as the leaderboards.
| Measure | Claude Haiku 5.5 | Mercury 3 |
|---|---|---|
| Spicy Index | 76.4 | 71.8 |
| Freedom Score | 77.8 | Not yet tested |
| Evidence | Tested 5 of 5 probe types · 24 runs | — |
| Range if the rest pass | 77.8–77.8 | — |
| Price | $0.20 per 1M mixed tokens (3 input : 1 output) | $0.325 per 1M mixed tokens (3 input : 1 output) |
| Reviews | Read the Claude Haiku 5.5 review | Read the Mercury 3 review |
Preliminary · freedom evidence pending
See both on the leaderboard →Current price
A start price answers a different question than the one you have. These are the tiers both models publish, matched setting for setting, in US dollars per billed unit with no conversion step in between.
Swipe horizontally to compare all fields.
| Tier | Claude Haiku 5.5 | Mercury 3 | Difference |
|---|---|---|---|
| Input | $0.1 / 1 million tokens | $0.2 / 1 million tokens | Claude Haiku 5.5 −50% |
| Cached input | $0.01 / 1 million tokens | $0.02 / 1 million tokens | Claude Haiku 5.5 −50% |
| Output | $0.5 / 1 million tokens | $0.7 / 1 million tokens | Claude Haiku 5.5 −28% |
Arithmetic on the published rates at each model's own default setting, not a quote. The console prices your actual settings before a request is accepted.
About this comparison
Every row here is read from the JSON Schema the endpoint validates against, so it matches what the API will really accept rather than a feature list written by hand.
Swipe horizontally to compare all fields.
| Controls and limits | Claude Haiku 5.5 | Mercury 3 |
|---|---|---|
| Supported tasks | chat | chat |
| Input context | 100,000 tokens | 1,000,000 tokens |
| Maximum output | 128,000 tokens | 131,072 tokens |
| Tool calling | Yes | Yes |
| Execution | Synchronous, with streaming | Synchronous, with streaming |
| Request timeout | 60 minutes | 10 minutes |
| Availability | Live | Live |
Can I swap the model ID without changing the request body?
The task lifecycle is shared; the body is not. Each endpoint publishes its own JSON Schema and the API validates against that, so this is the list to reconcile before a switch.
How to choose
Mercury 3 can return more in one reply: up to 131,072 tokens against the other model's ceiling.
Mercury 3 takes the longer prompt: up to 1,000,000 input tokens in a single request.
Compare
The model identifiers are anthropic/claude-haiku-5.5/chat and inception/mercury-3/chat, and both go in the same field of the same request.
Both return the response on the chat request. With streaming enabled, read the stream until it finishes; there is no media task to poll.
Both use the same submit-and-track flow, but their required inputs may differ. Check each model page before switching.
One key, one balance, one set of spend caps. Both bill to the same account in US dollars, and the per-key daily, monthly and lifetime limits apply to whichever one you call.
Questions developers ask
Claude Haiku 5.5 costs 28% less per million output tokens. Compare the input and cache rates below for longer conversations. Prices may change; check the estimate shown for your actual settings before submitting.
Claude Haiku 5.5 allows 60 minutes per task and Mercury 3 allows 10. Those are ceilings rather than typical times — most requests finish far sooner — but they are what your own client timeout has to survive.
Prices and capabilities shown here come from the current public model catalogue. Check each model page for its latest inputs and examples.