Skip to content
Not available in this workspace
OpenRouterOpenRouter
© 2026 OpenRouter, Inc

Product

  • Chat
  • Rankings
  • Benchmarks
  • Apps
  • Discover
  • Models
  • Collections
  • Providers
  • Pricing
  • Enterprise
  • Labs

Company

  • About
  • Blog
  • Careers
    Hiring
  • Privacy
  • Terms of Service
  • Support
  • Works With OR
  • Data

Developer

  • Documentation
  • API Reference
  • Developer Platform
  • Status

Connect

  • Discord
  • GitHub
  • LinkedIn
  • X
  • YouTube
Favicon for anthropic

Anthropic: Claude Sonnet 4.5

anthropic/claude-sonnet-4.5

Compare

Claude Sonnet 4.5 is Anthropic’s most advanced Sonnet model to date, optimized for real-world agents and coding workflows. It delivers state-of-the-art performance on coding benchmarks such as SWE-bench Verified, with improvements across system design, code security, and specification adherence. The model is designed for extended autonomous operation, maintaining task continuity across sessions and providing fact-based progress tracking.

Sonnet 4.5 also introduces stronger agentic capabilities, including improved tool orchestration, speculative parallel execution, and more efficient context and memory management. With enhanced context tracking and awareness of token usage across tool calls, it is particularly well-suited for multi-context and long-running workflows. Use cases span software engineering, cybersecurity, financial analysis, research agents, and other domains requiring sustained reasoning and tool use.

Modalities

In / Out Price

$3 / $15per 1M

Context

1M

Released

Sep 29, 2025

Knowledge Cutoff

Jan 2025

Compare
ProvidersPricingPerformanceUptimeBenchmarksAppsActivityFAQ

Providers

Different companies host the same model. OpenRouter routes your request to one of them based on the routing mode you pick — Balanced (price + speed), Nitro (fastest), or Exacto (highest tool-calling accuracy).

Pricing

The average price customers actually pay for this model, next to the prices providers post. Caching and discounts mean the price actually paid is often well below the listed one.

Performance

Throughput is how fast the model writes (tokens per second — higher is better). Latency is total round-trip time (lower is better). TTFT is time-to-first-token — how long before you see anything appear (lower is better).

Uptime

Uptime is the percentage of the past 3 days that at least one provider was responding to requests. Availability is the percentage of time that inference was successfully served. OpenRouter continuously monitors and uses the next-best provider when one returns an error.

Benchmarks

Scores on standardized evaluations. Higher percentages are better — and rank percentile shows where this model lands among all models on OpenRouter.

Apps

Public apps that send the most traffic to this model. Good signal for what real production workloads look like — and a hint at which use cases this model is best suited for.

Activity

Token volume and request traffic to this model over time.

Quick Start

Drop-in code to call this model. OpenRouter's API is OpenAI-compatible — most SDKs work by just swapping the base URL. The only thing that changes between models is the model slug below.

About Anthropic: Claude Sonnet 4.5

OpenRouter makes Anthropic: Claude Sonnet 4.5 available through a unified, OpenAI-compatible API using the model ID anthropic/claude-sonnet-4.5. Requests can be routed across 5 providers, including Amazon Bedrock (EU), Anthropic, Google Vertex (US), Claude Platform on AWS and Azure, with automatic failover when an endpoint is unavailable.

Anthropic: Claude Sonnet 4.5 accepts text, images and files such as PDFs and returns text. It has a 1,000,000-token context window and a maximum output of 64,000 tokens.

On OpenRouter, Anthropic: Claude Sonnet 4.5 costs $3.00/M input tokens and $15.00/M output tokens, with separate rates for Cache Read at $0.30/M tokens, Cache Write at $3.75/M tokens and Cache Write (1h) at $6.00/M tokens. Effective pricing can be lower when prompt caching applies. It was released on September 29, 2025; its knowledge cutoff is January 31, 2025.

More models from Anthropic

  • Claude Opus 5 (Fast)
  • Claude Opus 5
  • Claude Sonnet 5

Frequently asked questions

Claude Sonnet 4.5 is Anthropic’s most advanced Sonnet model to date, optimized for real-world agents and coding workflows. It delivers state-of-the-art performance on coding benchmarks such as SWE-bench Verified, with improvements across system design, code security, and specification adherence.

Claude Sonnet 4.5 costs $3.00/M input tokens and $15.00/M output tokens, with separate rates for Cache Read at $0.30/M tokens, Cache Write at $3.75/M tokens and Cache Write (1h) at $6.00/M tokens.

Claude Sonnet 4.5 has a 1,000,000 token context window. It supports up to 64,000 completion tokens.

Yes. Claude Sonnet 4.5 accepts tools and tool_choice for function calling. It also supports structured outputs via a JSON schema in response_format.

Claude Sonnet 4.5 accepts text, images and files such as PDFs as input and returns text.

Claude Sonnet 4.5 is served by 5 providers on OpenRouter: Amazon Bedrock (EU), Anthropic, Google Vertex (US), Claude Platform on AWS and Azure. Requests are routed to the best available provider, with automatic failover to the others, and you can pin or exclude providers with provider routing.

Claude Sonnet 4.5 was released on September 29, 2025. Its knowledge cutoff is January 31, 2025.

$3.00$15.00$0.301.97s35 tps
99.84%
$3.00$15.00$0.301.19s36 tps
99.76%
$3.00$15.00$0.301.10s34 tps
99.89%
$3.00$15.00$0.3024.00s3 tps
--
$3.00$15.00$0.301.93s45 tps
99.73%
$3.30$16.50$0.33----
--
$3.30$16.50$0.332.75s39 tps
100.00%

Throughput

45tok/s

P50, best across providers

Latency

1.10s

P50, best provider

AutoExacto Benchmarks
GPQA DiamondTAU-Bench
auto-routing
83.4%75.9%
Amazon Bedrock
82.6%76.4%
Amazon Bedrock (EU)
82.2%76.4%
Anthropic
82.0%75.9%
Claude Platform on AWS
79.5%76.9%
Google Vertex (US)
81.9%74.1%
Google Vertex (Global)
81.2%74.1%
Claude Platform on AWS
80.5%74.5%
Azure
78.0%74.0%
+1 more providers
Uptime (3d)

100.00%

Availability (3d)

99.96%

Availability over the last 3 days

Last 72 hours
Availability 99.96%
3 Days Ago2 Days AgoYesterdayNow

Availability over the last 24 hours

OpenRouter Availability
99.97%
Without Routing
96.65%

When an error occurs in an upstream provider, we can recover by routing to another healthy provider, if your request filters allow it. You can access per-provider uptime data programmatically through the Endpoints API. Learn more about our load balancing and customization options.

1.
Favicon for https://chataigne.ai/
Chataigne Clerk
new
15.7Btokens
2.
Favicon for https://claude.ai/apple-touch-icon.png
Claude Code
Claude Code is Anthropic's agentic coding tool that reads your entire codebase, plans and executes changes across files, runs tests, and iterates on failures, all from natural language prompts.
14.6Btokens
3.
Favicon for https://nousresearch.com
Hermes Agent
Hermes Agent is an open-source, self-improving AI agent by Nous Research that runs persistently with memory across sessions, and builds reusable skills from experience. It comes with 40+ built-in tools, including web search, browser automation, and vision, plus scheduled automations and subagents.
13.2Btokens
4.
Favicon for https://openclaw.ai/
OpenClaw
OpenClaw is an open-source AI agent that connects to your messaging apps and takes real actions on your behalf, from running commands and browsing the web to managing files and sending emails.
9.99Btokens
5.
Favicon for https://janitorai.com/
Janitor AI
Janitor AI is a chatbot platform where users create and chat with custom AI characters for interactive roleplay, storytelling, and immersive fiction.
9.91Btokens