Claude Opus 4.5

Claude Opus 4.5 is an Opus-tier model from Anthropic positioned for coding, long-horizon agents, computer use, and deep research.

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input · usd / 1m tok

$5.00

output · usd / 1m tok

$25.00

context window

200ktokens

modalities · in → out

pricing

base api ratesusd per 1m tokens

input: $5.00
output: $25.00
cache read: $0.50
cache write · default ttl: $6.25
cache write · 1h ttl: $10.00

providers

Anthropic hosts Claude Opus 4.5. Impossibl routes your request intelligently and handles failover automatically when a provider is down.

Anthropic

specifications

takes text and image in, gives text outanthropic/claude-opus-4-5

creatorAnthropic
model typeText generation
context window200,000 tokens
maximum outputnot published
input
takes text and image in, gives text out
outputtext
tool callingnot verified
releasednov 24, 2025
endpoint/v1/chat/completions

unknown means the public catalog does not establish that fact. a model's documented capabilities can differ from what a particular api supports. see the model documentation for integration details.

try it · your prompt, this model, live

# responses API
import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["IMPOSSIBL_API_KEY"],
    base_url="https://api.impossibl.com/v1",
)

resp = client.responses.create(
    model="anthropic/claude-opus-4-5",
    input="▌",
)
print(resp.output_text)

edit the prompt, then run

# responses API
import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["IMPOSSIBL_API_KEY"],
    base_url="https://api.impossibl.com/v1",
)

resp = client.responses.create(
    model="anthropic/claude-opus-4-5",
    input="▌",
)
print(resp.output_text)

edit the prompt, then run

benchmarks

intelligence index

23.7#52 of 90 models on the gateway

omniscience-4.1#43 of 86
gpqa81.0%#62 of 88
humanity’s last exam13.2%#67 of 89

Tau286.3%
GPQA81.0%
LiveCodeBench73.8%
MMMU-Pro71.2%
AA-LCR70.7%
AIME 202562.7%
IFBench43.0%
Terminal-Bench Hard40.9%
Humanity’s Last Exam13.2%
CritPt0.3%

Intelligence Index23.68
Omniscience Index-4.13
intelligence index (API)23.7

view source ↗all source data and breakdowns (json) ↗

each configuration is listed separately; these evaluations describe the tested model configuration, and performance and costs can differ on impossibl. unmeasured scores are omitted and api values keep their source units. last checked 2026-09-11.

compare Claude Opus 4.5 with other models

frontier labs and open weights, best-ranked firstusd / 1m tok · in / out

openai/gpt-6-astra$10.00 / $50.00compare →
meta/muse-spark-1.3$1.25 / $4.25compare →
zai/glm-5.3$1.40 / $4.40compare →
xai/grok-4.6$2.00 / $6.00compare →

impossibl models --all →

frequently asked questions

What is Claude Opus 4.5?

Claude Opus 4.5 is an Opus-tier model from Anthropic positioned for coding, long-horizon agents, computer use, and deep research. Its notable advance is token efficiency: a new effort parameter lets developers trade speed and cost against capability, and at medium effort it matches Sonnet 4.5 with far fewer output tokens.

How much does Claude Opus 4.5 cost?

Claude Opus 4.5 costs $5.00 per million input tokens and $25.00 per million output tokens through the Impossibl API. Cache reads cost $0.50 per million tokens; cache writes cost $6.25 per million tokens; cache writes with one-hour retention cost $10.00 per million tokens. All rates are in USD.

view the pricing table ↑

What is the context length of Claude Opus 4.5?

Claude Opus 4.5 has a 200,000-token context window through the Impossibl API.

What inputs and outputs does Claude Opus 4.5 support?

Claude Opus 4.5 accepts text and image as input. Claude Opus 4.5 returns text.

How do I use Claude Opus 4.5 through an API?

Claude Opus 4.5 is available through the Impossibl API. Use anthropic/claude-opus-4-5 as the model identifier with /v1/chat/completions. The quickstart explains how to create an API key and send your first request.

follow the api quickstart →

When was Claude Opus 4.5 released?

Anthropic released Claude Opus 4.5 on November 24, 2025.

Creator release announcement ↗

this page describes Claude Opus 4.5 as listed by the impossibl public api. prices and availability come from that catalog, refreshed here every five minutes. this is an impossibl offering, not a comparison of independent hosting-provider quotes. model descriptions and release dates, where available, use the creator sources linked under the answers above.

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