{"id":11464,"date":"2025-12-05T11:31:14","date_gmt":"2025-12-05T03:31:14","guid":{"rendered":"https:\/\/ai-stack.ai\/?p=11464"},"modified":"2025-12-05T11:34:59","modified_gmt":"2025-12-05T03:34:59","slug":"claude-opus-4-5","status":"publish","type":"post","link":"https:\/\/ai-stack.ai\/en\/claude-opus-4-5","title":{"rendered":"What is Claude Opus 4.5? Anthropic&#8217;s Most Intelligent AI Model Explained"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">Claude Opus 4.5 is Anthropic&#8217;s flagship AI model, released on November 24, 2025. Officially positioned as &#8220;the best model in the world for coding, agents, and computer use,&#8221; Opus 4.5 represents the pinnacle of the Claude 4.5 family. It delivers breakthrough performance in software engineering, enterprise workflows, and long-horizon autonomous tasks\u2014while dramatically reducing costs compared to previous Opus models.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Claude Opus 4.5 Core Specifications<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Here are the key technical specifications for Claude Opus 4.5:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td><strong>Specification<\/strong><\/td><td><strong>Value<\/strong><\/td><\/tr><tr><td>Context Window<\/td><td>200,000 tokens<\/td><\/tr><tr><td>Max Output<\/td><td>64,000 tokens<\/td><\/tr><tr><td>Knowledge Cutoff<\/td><td>March 2025<\/td><\/tr><tr><td>API Identifier<\/td><td>claude-opus-4-5-20251101<\/td><\/tr><tr><td>Input Pricing<\/td><td>$5 \/ million tokens<\/td><\/tr><tr><td>Output Pricing<\/td><td>$25 \/ million tokens<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Compared to<a href=\"https:\/\/www.anthropic.com\/claude\/opus\" target=\"_blank\" rel=\"noopener\"> Opus 4.1&#8217;s $15\/$75 pricing<\/a>, Opus 4.5 represents a 67% cost reduction, making top-tier AI capabilities more accessible than ever.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Key Capabilities of Claude Opus 4.5<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Coding and Software Engineering<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Claude Opus 4.5 achieves an industry-leading 80.9% on the<a href=\"https:\/\/www.anthropic.com\/news\/claude-opus-4-5\" target=\"_blank\" rel=\"noopener\"> SWE-bench Verified benchmark<\/a>, outperforming Google Gemini 3 Pro (76.2%) and OpenAI GPT-5.1-Codex-Max (77.9%). The model handles ambiguity like a senior engineer, autonomously analyzing and resolving complex bugs across multiple systems.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For developers who embrace<a href=\"https:\/\/ai-stack.ai\/en\/vibecoding2025\"> Vibe Coding<\/a>, Opus 4.5 paired with Claude Code can complete multi-day projects in hours, building more precise execution plans along the way.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>AI Agents and Automated Workflows<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">In the<a href=\"https:\/\/ai-stack.ai\/en\/mcp-ai-agents\"> AI Agent<\/a> domain, Opus 4.5 demonstrates exceptional long-horizon task handling. According to Anthropic&#8217;s testing, Opus 4.5 agents reach peak performance in just 4 iterations, while competing models couldn&#8217;t match that quality after 10. These agents can also learn from experience, storing insights to apply to future tasks.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">On the OSWorld computer-use benchmark, the Claude 4.5 family achieves 66.3%, making it the strongest &#8220;Computer Use&#8221; model available\u2014capable of operating desktop environments, launching applications, and handling file manipulation GUI workflows.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Enterprise Document Processing<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Opus 4.5 shows significant improvements in creating spreadsheets, presentations, and documents while maintaining context consistency across files. In Excel automation and financial modeling specifically, Fundamental Research Labs testing showed 20% accuracy improvement and 15% efficiency gains.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Exclusive Claude Opus 4.5 Features<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Effort Parameter<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Opus 4.5 is the only model that supports the effort parameter, allowing developers to set low, medium, or high levels via the API to balance performance and cost:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Medium Level<\/strong>: Matches Sonnet 4.5&#8217;s SWE-bench score while using 76% fewer output tokens<\/li>\n\n\n\n<li><strong>High Level<\/strong>: Exceeds Sonnet 4.5 by 4.3 percentage points while using 48% fewer tokens<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Hybrid Reasoning<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Opus 4.5 combines instant responses with extended thinking modes, automatically preserving all thinking blocks across multi-turn conversations to maintain reasoning continuity. This is particularly crucial for complex, long-running tasks.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Infinite Chat<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Paid users no longer encounter conversation length limits\u2014Opus 4.5 maintains context memory and consistency even in extremely long conversations.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Claude Opus 4.5 vs Competitors<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Comparison with Claude Sonnet 4.5<\/strong><\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td><strong>Comparison<\/strong><\/td><td><strong>Opus 4.5<\/strong><\/td><td><strong>Sonnet 4.5<\/strong><\/td><\/tr><tr><td>SWE-bench<\/td><td>80.9%<\/td><td>76.6%<\/td><\/tr><tr><td>Pricing (Input\/Output)<\/td><td>$5\/$25<\/td><td>$3\/$15<\/td><\/tr><tr><td>Effort Parameter<\/td><td>\u2713<\/td><td>\u2717<\/td><\/tr><tr><td>Positioning<\/td><td>Top-tier complex tasks<\/td><td>Everyday coding<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Comparison with<\/strong><a href=\"https:\/\/ai-stack.ai\/en\/gemini3\"><strong> <\/strong><strong>Gemini 3<\/strong><\/a><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Claude Opus 4.5 leads<a href=\"https:\/\/ai-stack.ai\/en\/gemini3\"> Gemini 3 Pro<\/a> on coding benchmarks, but on GPQA Diamond (PhD-level science questions), Gemini 3 Pro edges ahead with scores in the low 90s. On the MMLU general knowledge test, both achieve approximately 90%, with minimal difference.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Comparison with<\/strong><a href=\"https:\/\/ai-stack.ai\/en\/gpt-5-2\"><strong> <\/strong><strong>GPT-5<\/strong><\/a><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Opus 4.5 outperforms GPT-5.1-Codex-Max on SWE-bench (80.9% vs 77.9%), but OpenAI offers lower pricing ($1.25\/$10). The choice depends on your use case: choose Opus 4.5 for maximum coding capability, or consider GPT-5.1 for cost efficiency.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Claude Opus 4.5 Pricing and Cost Savings<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Standard API Pricing<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Input: $5 \/ million tokens<\/li>\n\n\n\n<li>Output: $25 \/ million tokens<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Cost-Saving Strategies<\/strong><\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Batch Processing<\/strong>: Get 50% off with batch processing\u2014input drops to $2.50, output to $12.50<\/li>\n\n\n\n<li><strong>Prompt Caching<\/strong>: Save up to 90% on repeated prompts\u2014writes cost $6.25\/million, reads just $0.50\/million<\/li>\n\n\n\n<li><strong>Effort Adjustment<\/strong>: Using medium effort significantly reduces token consumption<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Subscription Plans<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Opus 4.5 is included in the following<a href=\"https:\/\/platform.claude.com\/docs\/en\/about-claude\/pricing\" target=\"_blank\" rel=\"noopener\"> Claude subscription plans<\/a>:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Claude Pro ($20\/month)<\/li>\n\n\n\n<li>Claude Max<\/li>\n\n\n\n<li>Claude Team<\/li>\n\n\n\n<li>Claude Enterprise<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>How to Access Claude Opus 4.5<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Via Claude.ai Web Interface<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">All Pro, Max, Team, and Enterprise users can select the Opus 4.5 model directly on<a href=\"https:\/\/claude.ai\/\" target=\"_blank\" rel=\"noopener\"> Claude.ai<\/a>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Via API<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">import anthropic<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">client = anthropic.Anthropic()<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">message = client.messages.create(<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">&nbsp;&nbsp;&nbsp;&nbsp;model=&#8221;claude-opus-4-5-20251101&#8243;,<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">&nbsp;&nbsp;&nbsp;&nbsp;max_tokens=1024,<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">&nbsp;&nbsp;&nbsp;&nbsp;messages=[<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{&#8220;role&#8221;: &#8220;user&#8221;, &#8220;content&#8221;: &#8220;Hello, please analyze this code for me&#8221;}<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">&nbsp;&nbsp;&nbsp;&nbsp;]<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">)<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Via Cloud Platforms<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Opus 4.5 is also available on:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/aws.amazon.com\/bedrock\/\" target=\"_blank\" rel=\"noopener\">Amazon Bedrock<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/cloud.google.com\/vertex-ai\" target=\"_blank\" rel=\"noopener\">Google Cloud Vertex AI<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/azure.microsoft.com\/en-us\/blog\/introducing-claude-opus-4-5-in-microsoft-foundry\/\" target=\"_blank\" rel=\"noopener\">Microsoft Azure Foundry<\/a><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Who Should Use Claude Opus 4.5?<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">According to Anthropic&#8217;s official recommendations, the following users will get the most value from Opus 4.5:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Professional Software Developers<\/strong>: Those handling complex code refactoring and cross-system debugging<\/li>\n\n\n\n<li><strong>Financial Analysts<\/strong>: Those performing financial modeling, predictive analysis, and spreadsheet automation<\/li>\n\n\n\n<li><strong>Consultants and Accountants<\/strong>: Those processing large-scale document analysis and report generation<\/li>\n\n\n\n<li><strong>Enterprise Automation Teams<\/strong>: Those building long-horizon<a href=\"https:\/\/ai-stack.ai\/en\/chatgpt-agents2025\"> AI Agent workflows<\/a><\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">If your tasks are relatively straightforward,<a href=\"https:\/\/ai-stack.ai\/en\/claude3-7sonnet-vs-chatgpt4-5\"> Claude Sonnet 4.5<\/a> may be a more cost-effective choice.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Security and Prompt Injection Protection<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Opus 4.5 shows significant improvements in resistance to prompt injection attacks, making it the hardest-to-trick frontier model in the industry. According to Anthropic&#8217;s testing, single-attempt attack success rates are approximately 5%, but if attackers try 10 different attack methods, the success rate rises to around 33%.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Conclusion<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Claude Opus 4.5 represents the optimal balance between AI model practicality and accessibility. It not only leads the industry in coding and agent tasks but also makes top-tier AI capabilities available to more developers and enterprises through dramatically reduced pricing.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For professionals handling complex software engineering, long-horizon automation tasks, or enterprise-level document processing, Opus 4.5 is the most compelling option on the market today.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Further Reading:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/ai-stack.ai\/en\/claude3-7sonnet-vs-chatgpt4-5\">Claude 3.7 Sonnet vs ChatGPT 4.5: Complete Comparison<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/ai-stack.ai\/en\/mcp-ai-agents\">What is MCP? The New Standard for AI Agents<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/ai-stack.ai\/en\/gemini3\">Gemini 3: Complete Guide<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/ai-stack.ai\/en\/gpt-5-2\">GPT-5: In-Depth Analysis<\/a><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Official Resources:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/www.anthropic.com\/news\/claude-opus-4-5\" target=\"_blank\" rel=\"noopener\">Anthropic Claude Opus 4.5 Official Announcement<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/platform.claude.com\/docs\/en\/about-claude\/pricing\" target=\"_blank\" rel=\"noopener\">Claude API Pricing Documentation<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/platform.claude.com\/docs\/en\/about-claude\/models\/whats-new-claude-4-5\" target=\"_blank\" rel=\"noopener\">What&#8217;s New in Claude 4.5<\/a><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Claude Opus 4.5 is Anthropic&#8217;s flagship AI model, released on November 24, 2025. Officially positioned as &#8220;the best model in the world for coding, agents, and computer use,&#8221; Opus 4.5 represents the pinnacle of the Claude 4.5 family. It delivers breakthrough performance in software engineering, enterprise workflows, and long-horizon autonomous tasks\u2014while dramatically reducing costs compared to previous Opus models. Claude Opus 4.5 Core Specifications Here are the key technical specifications for Claude Opus 4.5: Specification Value Context Window 200,000 tokens Max Output 64,000 tokens Knowledge Cutoff March 2025 API Identifier claude-opus-4-5-20251101 Input Pricing $5 \/ million tokens Output Pricing $25 \/&#8230;<\/p>\n","protected":false},"author":253372376,"featured_media":11465,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_crdt_document":"","jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[96987604,96987592],"tags":[96988245],"class_list":["post-11464","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-ai-news","category-featured-articles","tag-claude-opus-2"],"blocksy_meta":[],"acf":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/ai-stack.ai\/wp-content\/uploads\/2025\/12\/%E6%A8%A1%E5%9E%8BA-42.jpg?fit=1920%2C1080&quality=100&ct=202603031250&ssl=1","jetpack_shortlink":"https:\/\/wp.me\/ph344V-2YU","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/ai-stack.ai\/en\/wp-json\/wp\/v2\/posts\/11464","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ai-stack.ai\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ai-stack.ai\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ai-stack.ai\/en\/wp-json\/wp\/v2\/users\/253372376"}],"replies":[{"embeddable":true,"href":"https:\/\/ai-stack.ai\/en\/wp-json\/wp\/v2\/comments?post=11464"}],"version-history":[{"count":1,"href":"https:\/\/ai-stack.ai\/en\/wp-json\/wp\/v2\/posts\/11464\/revisions"}],"predecessor-version":[{"id":11468,"href":"https:\/\/ai-stack.ai\/en\/wp-json\/wp\/v2\/posts\/11464\/revisions\/11468"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ai-stack.ai\/en\/wp-json\/wp\/v2\/media\/11465"}],"wp:attachment":[{"href":"https:\/\/ai-stack.ai\/en\/wp-json\/wp\/v2\/media?parent=11464"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ai-stack.ai\/en\/wp-json\/wp\/v2\/categories?post=11464"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ai-stack.ai\/en\/wp-json\/wp\/v2\/tags?post=11464"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}