Claude Haiku 5.5 API

anthropic/claude-haiku-5.5
Claude Haiku 5.5 is the fastest model in Anthropic's current lineup, positioned for high-volume, latency-sensitive tasks such as classification, extraction and routing. It carries a 1M-token context window and 128K maximum output.
Context
1M tokens
Input
$0.1 / 1M tokens
Output
$0.5 / 1M tokens
Released
Oct 7, 2026

Overview

What Is Claude Haiku 5.5 API?

Claude Haiku 5.5 is the fastest model in Anthropic's current lineup. Anthropic positions it for high-volume, latency-sensitive tasks such as classification, extraction and routing, and gives it the same 1M-token context window and 128K maximum output as Opus 5.5 and Sonnet 5.5 at a fraction of their price.

It uses the same tokenizer as Claude 4.7 and later, so the same text counts as roughly 30% more tokens than on Claude Haiku 4.5.

Technical Reference

DeveloperAnthropic
Model IDanthropic/claude-haiku-5.5
Release DateOctober 7, 2026
Context Window1,000,000 tokens
Max Output Tokens128,000 tokens
ModalitiesImage, Text → Text
ThinkingAdaptive, default effort medium
Knowledge cutoffJune 2026
CapabilitiesVision; tool use; multilingual; prompt caching

What Claude Haiku 5.5 Brings to the Table

Fastest in the lineup
Anthropic rates its comparative latency as the fastest of the four current models, ahead of Sonnet 5.5.

Frontier context at bulk price
The same 1M-token window as Opus 5.5 and Sonnet 5.5, from $0.10 per million input tokens against Opus at $4.

Adaptive thinking
The model decides how much to think, steered by the effort parameter, which defaults to medium here. Omit temperature, top_p and top_k — a non-default value for any of them returns a 400 error.

Cheap cache reads
Prompt cache reads cost 10% of the base input price, which matters when the same context is sent on every request.

API Pricing

  • Input: $0.13 / 1M tokens
  • Output: $0.65 / 1M tokens
  • Cached input: $0.013 / 1M tokens

Vendor-Reported Benchmarks

Published by Anthropic with the Claude Haiku 5.5 announcement, retrieved 7 October 2026. These are the vendor's own figures and have not been independently reproduced.

  • GDPval-AA v2.1: 1620
  • AA-Briefcase v1.1: 1578
  • OSWorld 2.1: 72.4% (offline subset)
  • Humanity's Last Exam: 45.9% without tools, 57.4% with tools
  • Terminal-Bench 4.0: 39.2%
  • FrontierCode 1.1: 46.4%
  • Chartography: 46.4%

Where Claude Haiku 5.5 Makes the Most Sense

Work measured in millions of calls
Classification, routing and extraction, where the price per request decides whether the pipeline is viable.

Interfaces people wait on
Suggestions and inline assistance, where the fastest model in the family is the point.

Triage before escalation
Haiku handles the volume and hands the hard cases to Opus or Sonnet.

Sources: https://www.anthropic.com/claude-haiku-5-5 · https://platform.claude.com/docs/en/models/haiku-5-5/overview

Uptime and performance

  • Uptime (24h): 100%
  • Uptime (7d): 99.0%
  • Availability (24h): 100%
  • Error rate (24h): 0%
  • End-to-end latency (24h median): 6.2s
  • Time to first token (24h median): 742ms
  • Throughput (24h median): 118.3 tok/s

Measured on the AI/ML API gateway across live traffic. Figures are medians unless stated. Last updated 2026-10-12.

Use cases

  • Classification and routing: the work Anthropic names first — deciding what a request is and where it goes, at volume.
  • Extraction: pulling structured fields out of documents, tickets and screenshots.
  • Latency-sensitive interfaces: autocomplete, inline suggestions and anything a person waits on.
  • High-volume pipelines: the cheapest model in the current Claude lineup, which decides what is affordable to run on every record.
  • Long-document triage: a 1M-token window on a model priced for bulk work.

How to use Claude Haiku 5.5 API

Install any OpenAI-compatible SDK, point it at api.aimlapi.com/v1, and set the model to anthropic/claude-haiku-5.5.
import requests

r = requests.post(
    "https://api.aimlapi.com/v1/chat/completions",
    headers={"Authorization": "Bearer " + AIMLAPI_KEY},
    json={
      "model": "anthropic/claude-haiku-5.5",
      "messages": [
        {
          "role": "user",
          "content": "Hello!"
        }
      ]
    },
)
print(r.json())
const r = await fetch("https://api.aimlapi.com/v1/chat/completions", {
  method: "POST",
  headers: {
    Authorization: "Bearer " + process.env.AIMLAPI_KEY,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "model": "anthropic/claude-haiku-5.5",
    "messages": [
      {
        "role": "user",
        "content": "Hello!"
      }
    ]
  }),
});
console.log(await r.json());
curl -X POST https://api.aimlapi.com/v1/chat/completions \
  -H "Authorization: Bearer $AIMLAPI_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"anthropic/claude-haiku-5.5","messages":[{"role":"user","content":"Hello!"}]}'

OpenAI-compatible — swap the base URL and it works with your existing SDK.

Claude Haiku 5.5 API Pricing

TypePrice
Input
$0.1 / 1M tokens
Output
$0.5 / 1M tokens
Cached input
$0.01 / 1M tokens

Anthropic prices this model in two tiers by prompt length: the rates shown apply to prompts up to 100,000 tokens, and prompts above that are charged five times more ($0.65 in / $3.25 out per 1M tokens). Batch requests are half price.

Claude Haiku 5.5 Benchmarks

BenchmarkScoreWhat it measuresSourceRetrieved
GDPval-AA
1620
Economically valuable knowledge work across occupations, scored as an Elo-style ratingSourceOctober 7, 2026
AA-Briefcase
1578
Multi-document office work: reading a brief, pulling the relevant facts and producing the deliverableSourceOctober 7, 2026
OSWorld
72.4%
Computer-use across real desktop applicationsSourceOctober 7, 2026
Humanity's Last Exam
45.9%
Expert-level questions across many domainsSourceOctober 7, 2026
Terminal-Bench 4
39.2%
Autonomous shell and terminal task completion, fourth releaseSourceOctober 7, 2026
FrontierCode
46.4%
Agentic coding on frontier-level software engineering tasksSourceOctober 7, 2026
Chartography
46.4%
Visual reasoning over charts, plots and diagramsSourceOctober 7, 2026
Intelligence
43.4
Composite score across standardised reasoning, knowledge and problem-solving evaluations, measured independently by Artificial AnalysisSourceOctober 7, 2026

Figures published by Anthropic with the Claude Haiku 5.5 announcement (anthropic.com/claude-haiku-5-5), retrieved 7 October 2026. Vendor-reported and not independently reproduced. OSWorld 2.1 is the offline subset; Humanity's Last Exam is the no-tools score, rising to 57.4% with tools.

Claude Haiku 5.5 vs other models

ModelInputOutputContextBest for
$0.1 / 1M tokens
$0.5 / 1M tokens
1M tokens
High-volume, low-latency tasks
$2 / 1M tokens
$10 / 1M tokens
1M tokens
Multimodal reasoning
$4 / 1M tokens
$20 / 1M tokens
1M tokens
Complex agentic coding and enterprise workflows
$5 / 1M tokens
$25 / 1M tokens
200K tokens
Chat + assistants

Frequently asked questions

Claude Haiku 5.5 is Anthropic's fastest current model. Anthropic positions it for high-volume, latency-sensitive tasks such as classification, extraction and routing, and lists it as the fastest in the current lineup.

$0.13 per 1M input tokens and $0.65 per 1M output tokens through AI/ML API. Cached input reads are $0.013 per 1M tokens, following Anthropic's rate of 10% of the base input price.

1M tokens, with a maximum output of 128K tokens on the synchronous endpoint. Anthropic notes that batch requests can reach 300K output tokens with a beta header.

It uses adaptive thinking: the model decides how much to think, steered by the effort parameter. The default effort on Haiku 5.5 is medium.

Yes. Anthropic states that all current Claude models support text and image input, text output, multilingual capabilities, vision and tool use.

Both carry a 1M-token context window and 128K max output. Anthropic rates Haiku 5.5 as the fastest in the lineup and Sonnet 5.5 as the best combination of speed and intelligence. Sonnet 5.5 is listed at $2 / $10 per million tokens against Haiku's from $0.10 / from $0.50.

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