Claude Sonnet 4.5 model profile

Profile facts

Profile type

Model research profile

Provider or publisher

Anthropic

Context window

1,000,000 tokens

Snapshot date

2026-09-06

Knowledge cutoff

2025-01-31

Reference catalog ID

anthropic/claude-sonnet-4.5

When to pick Claude Sonnet 4.5

Claude Sonnet 4.5 is a reference profile: Anthropic publishes it, Kendr documents it for comparison, and it carries no Kendr alias to call.

Each condition below is derived from this model's own values in the 2026-09-06 snapshot, compared only against models publishing the same field.

• Reach for it when the input includes images. The snapshot records image input, so screenshots, scans, and diagrams can be sent directly instead of described.
• Reach for it when the model has to call tools. Tool calling is recorded in the snapshot, so this route can drive an agent loop rather than only answer in prose.
• Look elsewhere when you need to call it through Kendr today. This is a research reference profile with no Kendr alias. The facts and evidence here are published for comparison; the model is not routable on Kendr.
• Look elsewhere when the work does not justify the rate. At $3 in and $15 out per 1M tokens, this is in the most expensive tenth of the 146 models publishing both rates. Route routine or high-volume traffic to a cheaper model and keep this one for work that needs it.

Context, modalities, and identity

Claude Sonnet 4.5 accepts text, image, and file and returns text. The snapshot records file input, prompt caching, reasoning controls, structured output, text generation, tool calling, vision, and web search pricing as capabilities or interfaces.

Provider or publisher

Anthropic

Context window

1,000,000 tokens

Maximum output

64,000 tokens

Input modalities

text, image, and file

Output modalities

text

Knowledge cutoff

2025-01-31

Model overview

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.

Reference model ID

anthropic/claude-sonnet-4.5

Canonical version

anthropic/claude-4.5-sonnet-20250929

Hugging Face ID

Not separately documented

Capabilities and supported controls

Capabilities and parameters are reported from the dated catalog and source records; their presence does not guarantee identical behavior across every provider route.

Supported parameters

include_reasoning, max_completion_tokens, max_tokens, reasoning, response_format, stop, structured_outputs, temperature, tool_choice, tools, top_k, top_p

• file input
• prompt caching
• reasoning controls
• structured output
• text generation
• tool calling
• vision
• web search pricing

Dated pricing snapshot

The dated reference snapshot lists $3 input and $15 output per million tokens. Cached input is $0.3 per million tokens.

These are dated third-party reference prices, not Kendr prices or an availability offer. Routes, tiers, caching, region, and provider policy can change the landed price.

Price date

2026-09-06

Input

$3 per 1M tokens

Cached input

$0.3 per 1M tokens

Output

$15 per 1M tokens

Provider routes, performance, and uptime

The snapshot retains 7 provider endpoints. Provider prices, context limits, p50 performance, and uptime can differ by route and are not Kendr guarantees.

Active provider endpoints

7

Best p50 latency

1.30 s

Best p50 throughput

74 tok/s

Availability with routing

99.99% over the sampled window

Availability without routing

98.37% over the sampled window

Performance date

2026-09-06

Benchmark evidence and limitations

The 2026-09-06 snapshot includes 1 Artificial Analysis index, 11 Design Arena categories, and AutoExacto results for 10 provider observations. Publisher-reported launch results are labeled and are not presented as Kendr measurements; scores from different suites are not treated as interchangeable.

Third-party catalog fields normalized from the cited model dataset; benchmark methodology and coverage differ by source.

Coding Index

52.1

AutoExacto coverage

10 provider observations over 32 days

AutoExacto provider benchmarks

Rolling provider observations from the cited third-party benchmark view. The lookback is 32 days; GPQA Diamond and TAU-Bench Airline measure different abilities and should not be blended into one score.

Popularity and market context

Claude Sonnet 4.5 ranked #80 in the cited trailing-7-day third-party catalog usage dataset as of 2026-09-06. Observed within the cited trailing-7-day third-party catalog usage dataset; this is not global AI market share.

Third-party catalog rank

#80

Global market share

Not inferred

Observation date

2026-09-06

Frequently asked questions

Sources and evidence dates

1. Claude Sonnet 4.5 third-party catalog record (catalog, checked 2026-09-06)
2. Third-party model catalog methodology (methodology, checked 2026-09-06)
3. Anthropic official model documentation (primary, checked 2026-09-06)
4. Artificial Analysis capability indices methodology (benchmark, checked 2026-09-06)
5. Design Arena leaderboard and methodology (benchmark, checked 2026-09-06)
6. Claude Sonnet 4.5 third-party catalog record (benchmark, checked 2026-09-06)