Anthropic's most capable model delivers best-in-class reasoning and writing quality, but the steep output cost demands genuinely complex use cases to justify it.
82
Coding
95
Writing
93
Research
10
Images
28
Value
90
Long Context
Use this when
Complex multi-step reasoning, long-document analysis, and high-stakes writing tasks where output quality is non-negotiable.
Skip this if
You need fast turnaround, are running high-volume batch jobs, or your tasks don't demand flagship-level reasoning — Claude Sonnet 4.6 covers 80% of use cases at a fraction of the cost.
Pricing
$5.00/1M in
$25.00/1M out
→0%since May 2026
Context
200k tokens
Speed
Deliberate
Claude Opus 4.5specs & pricing
Verified Sep 4, 2026 against the AI Gateway catalog
Pricing is $5 input / $25 output per 1M tokens — identical output cost to GPT-5.4 tier models. Note the 'Supersedes Claude 4 Haiku' label appears to be a data anomaly; Opus 4.5 is the top-tier model, not a Haiku replacement. Confirm model availability on the Anthropic API dashboard as Opus-tier models sometimes have access restrictions.
Exceptional instruction-following and nuance in complex, multi-constraint prompts
200K context window handles entire codebases, legal documents, or research corpora in a single pass
Notably strong at structured reasoning, argument analysis, and synthesis across long inputs
Anthropic's safety tuning produces reliable, consistent outputs with fewer hallucinations on factual tasks
Weaknesses
At $25/1M output tokens, it's expensive for high-volume or iterative workflows compared to Claude Sonnet 4.6 or GPT-5.4
Slower inference makes it poorly suited for real-time or latency-sensitive applications
No native image generation capability; multimodal input only, not output
Real-world use cases
What people actually use Claude Opus 4.5 for.
Analyzing a 150-page legal contract to identify risk clauses and summarize obligations by party
Writing a detailed technical architecture proposal with trade-off analysis across multiple engineering approaches
Synthesizing contradictory findings across 20+ research papers into a coherent literature review
How Claude Opus 4.5 compares
The nearest models people weigh against it, and what actually separates them.
vs Claude 3.5 Sonnet — Against Claude 3.5 Sonnet (Anthropic), Claude Opus 4.5 runs about 17% cheaper per token and answers slower. Which one wins depends on whether context depth or latency is your constraint.
vs Claude Fable 5 — Against Claude Fable 5 (Anthropic), Claude Opus 4.5 runs about 50% cheaper per token and gives up 5x on context. Take Claude Opus 4.5 unless you specifically need what Claude Fable 5 does better.
vs Claude Fable 5.1 — Against Claude Fable 5.1 (Anthropic), Claude Opus 4.5 runs about 50% cheaper per token and gives up 5x on context. Take Claude Opus 4.5 unless you specifically need what Claude Fable 5.1 does better.
Price History
Claude Opus 4.5 pricing over time
→0% since May 31
90 data points · tracked daily since May 31, 2026
Ready to try it?
Start using Claude Opus 4.5
Complex multi-step reasoning, long-document analysis, and high-stakes writing tasks where output quality is non-negotiable.. Start free — no card required.
Claude 3.5 Sonnet is Anthropic's mid-cycle flagship model, balancing strong reasoning, coding, and instruction-following with a 200K context window. It sits between Haiku and Opus in Anthropic's lineup, offering near-flagship quality at a lower cost than top-tier models.
Verdict
One of the best models for coding and complex instruction-following, but its premium pricing demands premium use cases.
Quality score
81%
Pricing
$6.00/1M in
$30.00/1M out
Speed
Balanced
3/5 speed
Context
200k tokens
Pricing at $6 input / $30 output per million tokens is significantly higher than GPT-4o ($2.50/$10). Best accessed via Anthropic API or Amazon Bedrock. Claude 3.5 Sonnet (October 2024 version) supersedes the June 2024 release with improved performance.
Anthropic's new Mythos-class flagship and the most capable coding model anyone can use — 80.3% SWE-Bench Pro, an 11-point jump over Opus 4.8. 1M context, 128K output, native parallel subagents. Released June 9, 2026.
Verdict
New global #1 — 80.3% SWE-Bench Pro, the most capable model generally available.
Quality score
98%
Pricing
$10.00/1M in
$50.00/1M out
Speed
Deliberate
2/5 speed
Context
1M tokens
Launched June 9, 2026 as the public, Mythos-class release. Available on the Claude API, Microsoft Foundry, and Google Vertex AI. Free for all users until June 22, 2026. Same underlying model as Claude Mythos 5, with safeguards that block specific high-risk cyber responses.
Coding leaderSWE-Bench Pro #1Mythos-classParallel subagentsAgenticLong contextPremiumNew
Best for
The hardest coding tasks, autonomous multi-step agents, and frontier-grade reasoning
Anthropic's September 1, 2026 frontier release and the new capability ceiling for coding, agents, and scientific work. Base pricing is unchanged at $10/$50, but cache reads dropped 75% to $0.25/1M — roughly 25% cheaper on typical workloads and up to 45% cheaper on agentic ones. 1M context, 128K output, adaptive thinking always on.
Verdict
New frontier leader — better than Fable 5 on every published benchmark, and cheaper to run.
Quality score
98%
Pricing
$10.00/1M in
$50.00/1M out
Speed
Deliberate
2/5 speed
Context
1M tokens
Released September 1, 2026 alongside Claude Mythos 5.1, the first update to the Mythos-class line since Fable 5 on June 9. API ID claude-fable-5-1; generally available on the Claude API, Amazon Bedrock, Google Cloud, and Microsoft Foundry. Published launch numbers (Fable 5.1 / Fable 5 / Opus 5 / GPT-5.6 Sol): Terminal-Bench-Science 0.1 52.6 / 24.7 / 29.0 / 22.4; Terminal-Bench 4.0 55.8 / 42.0 / 52.3 / 37.3; CursorBench 3.2.0 73.4 / 70.5 / 70.0 / 67.2; AutomationBench 31.4 / 17.1 / 26.9 / 19.6; OSWorld 2.0 strict 41.7 / 36.1 / 39.6; Humanity's Last Exam (no tools) 60.9 / 57.8 / 56.6; GDPval-AA v2 1853 / 1723 / 1824 / 1711. GDPval-AA v2 is rescaled from the v1 numbers quoted on the Fable 5 page and is not directly comparable to them.
Anthropic: Claude Opus 4.5 (Anthropic) is now indexed. It supersedes Claude 4 Haiku. Anthropic's most capable model delivers best-in-class reasoning and writing quality, but the steep output cost demands genuinely complex use cases to justify it.
Claude Opus 4.5 costs $5 per million input tokens and $25 per million output tokens on the API, with cached input at $0.5 per million. A month of 10M input and 2M output tokens runs about $100.00 at list price, before any batch or caching discounts.
What is the context window of Claude Opus 4.5?
Claude Opus 4.5 has a 200k tokens context window, with up to 64k tokens of output per response. That is the total of prompt plus response the model can hold in one request.
What is the knowledge cutoff of Claude Opus 4.5?
Claude Opus 4.5's training data runs through May 2025, and the model was released on November 24, 2025. For anything after that date it needs web search or documents in the prompt.
What is Claude Opus 4.5 best for?
Claude Opus 4.5 is best for complex multi-step reasoning, long-document analysis, and high-stakes writing tasks where output quality is non-negotiable.. It is a strong fit when that workflow matters more than the tradeoffs around balanced pricing and deliberate speed.
When should I avoid Claude Opus 4.5?
You need fast turnaround, are running high-volume batch jobs, or your tasks don't demand flagship-level reasoning — Claude Sonnet 4.6 covers 80% of use cases at a fraction of the cost.
What is a cheaper alternative to Claude Opus 4.5?
Claude 3.5 Sonnet (Anthropic) at $6.00/1M/1M input against Claude Opus 4.5's $5.00/1M/1M. One of the best models for coding and complex instruction-following, but its premium pricing demands premium use cases. Compare it first if Claude Opus 4.5's pricing is the thing stopping you.
What is a faster alternative to Claude Opus 4.5?
Claude Fable 5 — deliberate against Claude Opus 4.5's deliberate, with 1M tokens of context. Worth the swap when response time is what your users notice rather than the last few points of reasoning depth.
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