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Anthropic vs Anthropic

Claude 4.5 Sonnet vs Claude 4 Sonnet

Compare Claude 4.5 Sonnet and Claude 4 Sonnet across pricing, context window, capabilities, benchmarks, and API access to choose the better fit for reasoning-heavy tasks versus reasoning-heavy tasks.

Overview ↓ Pricing ↓ Capabilities ↓ Benchmarks ↓ Community ↓ Tools ↓ Verdict ↓ FAQ ↓ Related ↓

Overview Comparison

Structured side-by-side differences for the highest-signal model metadata.

Claude 4.5 Sonnet
Claude 4 Sonnet

Provider

The entity that currently provides this model.

Claude 4.5 Sonnet Anthropic
Claude 4 Sonnet Anthropic

Model ID

The routed model identifier exposed by upstream providers.

Claude 4.5 Sonnet anthropic/claude-sonnet-4.5
Claude 4 Sonnet anthropic/claude-sonnet-4

Input Context Window

The number of tokens supported by the input context window.

Claude 4.5 Sonnet 200,000 tokens
Claude 4 Sonnet 200,000 tokens

Maximum Output Tokens

The number of tokens that can be generated by the model in a single request.

Claude 4.5 Sonnet 64,000 tokens tokens
Claude 4 Sonnet 64,000 tokens tokens

Open Source

Whether the model's code is available for public use.

Claude 4.5 Sonnet No
Claude 4 Sonnet No

Release Date

When the model was first released.

Claude 4.5 Sonnet Sep 29, 2025
Claude 4 Sonnet May 22, 2025

Knowledge Cut-off Date

When the model's knowledge was last updated.

Claude 4.5 Sonnet September 2025
Claude 4 Sonnet 2025-01-31

API Providers

The providers that currently expose the model through an API.

Claude 4.5 Sonnet
OpenRouter
Claude 4 Sonnet
OpenRouter

Modalities

Types of data each model can process or return.

Claude 4.5 Sonnet
Text Image File Code
Claude 4 Sonnet
Text Image File Code

Pricing Comparison

Compare current token pricing before you choose the cheaper or more scalable API option.

Claude 4.5 Sonnet Anthropic
Input price $3.00 Per 1M tokens
Output price $15.00 Per 1M tokens
Claude 4 Sonnet Anthropic
Input price $3.00 Per 1M tokens
Output price $15.00 Per 1M tokens

Capabilities Comparison

See where each model overlaps, where they differ, and which one supports more of the features you care about.

Capability
Claude 4.5 Sonnet
Claude 4 Sonnet
Advanced Reasoning Applies multi-step reasoning to problems in domains including finance, law, medicine, and STEM, with improved knowledge depth compared to earlier Claude generations.
Claude 4.5 Sonnet Supported
Claude 4 Sonnet —
Agentic Task Execution Designed to sustain coherent, autonomous work on complex multi-step tasks — including file editing, command execution, and test running — across extended sessions.
Claude 4.5 Sonnet Supported
Claude 4 Sonnet —
Agentic Tool Use Supports tool calling and multi-step workflows, enabling integration with external APIs and use as a subagent in complex AI pipelines.
Claude 4.5 Sonnet —
Claude 4 Sonnet Supported
Code Generation Generates, edits, and debugs code across complex software engineering tasks, ranking at the top of the SWE-bench Verified leaderboard for real-world coding ability.
Claude 4.5 Sonnet Supported
Claude 4 Sonnet Supported
Computer Use Can interact with real computer interfaces such as navigating GUIs, managing files, and running tools, scoring 61.4% on the OSWorld benchmark.
Claude 4.5 Sonnet Supported
Claude 4 Sonnet —
Configurable Parameters Exposes numeric configuration options such as temperature and token limits, giving developers fine-grained control over output behavior.
Claude 4.5 Sonnet —
Claude 4 Sonnet Supported
File
Claude 4.5 Sonnet Supported
Claude 4 Sonnet Supported
Hybrid Reasoning Supports both standard fast responses and an optional extended thinking mode that works through problems step by step, adapting reasoning depth to task complexity.
Claude 4.5 Sonnet —
Claude 4 Sonnet Supported
Image
Claude 4.5 Sonnet Supported
Claude 4 Sonnet Supported
Large Context Window Processes up to 200,000 tokens in a single request, enabling analysis of long documents, large codebases, or extended conversation histories without truncation.
Claude 4.5 Sonnet Supported
Claude 4 Sonnet Supported
MCP Integration Compatible with Model Context Protocol (MCP) servers, allowing the model to connect to external data sources and tools through a standardized interface.
Claude 4.5 Sonnet Supported
Claude 4 Sonnet —
Reasoning
Claude 4.5 Sonnet Supported
Claude 4 Sonnet Supported
Structured Output
Claude 4.5 Sonnet Supported
Claude 4 Sonnet —
Text
Claude 4.5 Sonnet Supported
Claude 4 Sonnet Supported
Tool Use Supports structured tool calling so the model can invoke external functions, APIs, or services as part of a response, enabling dynamic, action-oriented workflows.
Claude 4.5 Sonnet Supported
Claude 4 Sonnet —
Tools
Claude 4.5 Sonnet Supported
Claude 4 Sonnet Supported
Vision & Multimodal Input Accepts images and PDFs alongside text, allowing the model to analyze visual content and documents within the same request.
Claude 4.5 Sonnet —
Claude 4 Sonnet Supported

Benchmark Comparison

Shared benchmark rows make it easier to compare performance where both models have published scores.

Benchmark Claude 4.5 Sonnet Claude 4 Sonnet
AIME 2024
American math olympiad problems
Claude 4.5 Sonnet N/A
Claude 4 Sonnet 40.7%
GPQA Diamond
PhD-level science questions (biology, physics, chemistry)
Claude 4.5 Sonnet 72.7%
Claude 4 Sonnet 68.3%
HLE
Questions that challenge frontier models across many domains
Claude 4.5 Sonnet 7.1%
Claude 4 Sonnet 4.0%
LiveCodeBench
Real-world coding tasks from recent competitions
Claude 4.5 Sonnet 59.0%
Claude 4 Sonnet 44.9%
MATH-500
Undergraduate and competition-level math problems
Claude 4.5 Sonnet N/A
Claude 4 Sonnet 93.4%
MMLU-Pro
Expert knowledge across 14 academic disciplines
Claude 4.5 Sonnet 86.0%
Claude 4 Sonnet 83.7%
OSWorld
Autonomous computer use and desktop tasks
Claude 4.5 Sonnet 61.4%
Claude 4 Sonnet N/A
SciCode
Scientific research coding and numerical methods
Claude 4.5 Sonnet 42.8%
Claude 4 Sonnet 37.3%
SWE-bench Verified
Real GitHub issues requiring multi-file code fixes
Claude 4.5 Sonnet 77.2%
Claude 4 Sonnet N/A
Terminal-Bench
Agentic coding and terminal command tasks
Claude 4.5 Sonnet 50.0%
Claude 4 Sonnet N/A
τ²-bench Retail
Agentic tool use in retail scenarios
Claude 4.5 Sonnet 86.2%
Claude 4 Sonnet N/A
τ²-bench Telecom
Agentic tool use in telecom scenarios
Claude 4.5 Sonnet 98.0%
Claude 4 Sonnet N/A
Community discussion

What Reddit discussions say about Claude 4.5 Sonnet vs Claude 4 Sonnet

Claude 4.5 Sonnet and Claude 4 Sonnet are both surfacing live Reddit discussions, giving this comparison a community layer beyond specs and benchmarks.

The most visible threads right now are clustered in r/ClaudeAI, r/singularity, r/LocalLLaMA. 1 thread is showing up in both models' discussion sets, which is useful for side-by-side evaluation.

Claude 4 Sonnet r/ClaudeAI 1,892 upvotes 443 comments September 29, 2025
Introducing Claude Sonnet 4.5

https://preview.redd.it/lm1pxnzzl4sf1.png?width=2160&format=png&auto=webp&s=fe15e1db93ef31b6d39bf959715f67701ede2271

Introducing Claude Sonnet 4.5—the best coding model in the world. 

It's the strongest model for building complex agents, the best model for computer use, and it shows substantial gains on tests of reasoning and math.

We're also introducing upgrades across all Claude surfaces

**Claude Code**

* The terminal interface has a fresh new look
* The new VS Code extension brings Claude to your IDE. 
* The new checkpoints feature lets you confidently run large tasks and roll back instantly to a previous state, if needed

**Claude App**: 

* Claude can use code to analyze data, create files, and visualize insights in the files & formats you use. Now available to all paid plans in preview. 
* The Claude for Chrome extension is now available to everyone who joined the waitlist last month

**Claude Developer Platform**: 

* Run agents longer by automatically clearing stale context and using our new memory tool to store and consult more information.
* The Claude Agent SDK gives you access to the same core tools, context management systems, and permissions frameworks that power Claude Code

We're also releasing a temporary research preview called **"Imagine with Claude"**

* In this experiment, Claude generates software on the fly. No functionality is predetermined; no code is prewritten.
* Available to Max users for 5 days. [Try it out](https://claude.ai/imagine)

Claude Sonnet 4.5 is available everywhere today—on the Claude app and Claude Code, the Claude Developer Platform, natively and in Amazon Bedrock and Google Cloud's Vertex AI.

Pricing remains the same as Sonnet 4.

[Read the full announcement](https://www.anthropic.com/news/claude-sonnet-4-5)

Open Reddit thread
Claude 4.5 Sonnet + Claude 4 Sonnet r/singularity 1,358 upvotes 188 comments September 29, 2025
Claude 4.5 Sonnet is here

[https://www.anthropic.com/news/claude-sonnet-4-5](https://www.anthropic.com/news/claude-sonnet-4-5)

Open Reddit thread
Claude 4 Sonnet r/ClaudeAI 1,222 upvotes 229 comments February 17, 2026
This is Claude Sonnet 4.6: our most capable Sonnet model yet.

Claude Sonnet 4.6 is a full upgrade across coding, computer use, long-context reasoning, agent planning, knowledge work, and design. It also features a 1M token context window in beta.

Sonnet 4.6 has improved on benchmarks across the board. It approaches Opus-level intelligence at a price point that makes it practical for far more tasks.

It also shows a major improvement in computer use skills. Early users are seeing human-level capability in tasks like navigating a complex spreadsheet or filling out a multi-step web form.

Claude Sonnet 4.6 is available now on all plans, Cowork, Claude Code, our API, and all major cloud platforms. We've also upgraded our free tier to Sonnet 4.6 by default.

Learn more: [anthropic.com/news/claude-sonnet-4-6](http://anthropic.com/news/claude-sonnet-4-6)

Open Reddit thread
View more discussions →

AI tools related to Claude 4.5 Sonnet vs Claude 4 Sonnet

These tools are closely connected to one or both models in this comparison and can help you evaluate real-world fit.

AI Chatbot

LongShot AI

LongShot AI is an AI-powered content creation platform built to help users plan, generate, and optimize articles for search engines like Google, ChatGPT, Perplexity, and Gemini. It provides features such as real-time content generation, fact-checking, semantic SEO, and custom AI tools to produce high-quality, SEO-optimized content. LongShot AI balances creativity with optimization to help users create content that engages audiences and improves search rankings.

Free 0 visits 30 saves
AI Chatbot

Claudeai.ai

Claudeai.ai is a platform powered by Anthropic's Claude 2 language model. It provides global access to Claude 2's features, including support for processing various text files, a 100K token context limit, and the ability to interact with up to 5 files at once. While not affiliated with Anthropic, Claudeai.ai uses the Claude 2 API to offer a user experience similar to the official website, accessible without regional restrictions.

Free 0 visits 17 saves
AI Writing Assistants

Sudowrite

Sudowrite is an AI writing assistant tailored for fiction authors, novelists, and screenwriters. It helps users overcome writer's block, brainstorm concepts, generate prose, expand scenes, refine sentences, and receive feedback on drafts. By utilizing various large language models, it supports the entire writing process—from initial outlining to final editing—to make writing more efficient, enjoyable, and collaborative.

Free 1 visits 17 saves
AI Agent

Engine

Engine is a suite of LLM-powered no-code tools that enables the creation of hosted API endpoints, HTML pages, and images using natural language. Additionally, it functions as an AI software engineer for teams, integrating with platforms like Jira, Trello, and Linear to convert tickets into pull requests, helping to automate development tasks and clear backlogs.

Free 0 visits 6 saves

Which model should you choose?

Use the summary below to decide which model better fits your workflow, budget, and feature requirements.

Best fit for

Claude 4.5 Sonnet

Claude 4.5 Sonnet is a stronger fit for reasoning-heavy tasks, tool-augmented workflows, multimodal applications.

Best fit for

Claude 4 Sonnet

Claude 4 Sonnet is a stronger fit for reasoning-heavy tasks, tool-augmented workflows, multimodal applications.

Verdict

Choose Claude 4.5 Sonnet if you prioritize reasoning-heavy tasks, tool-augmented workflows, multimodal applications. Choose Claude 4 Sonnet if your workflow depends more on reasoning-heavy tasks, tool-augmented workflows, multimodal applications.

FAQ

Common questions about Claude 4.5 Sonnet vs Claude 4 Sonnet

What is the main difference between Claude 4.5 Sonnet and Claude 4 Sonnet?

Claude 4.5 Sonnet leans toward reasoning-heavy tasks, tool-augmented workflows, multimodal applications, while Claude 4 Sonnet is better suited to reasoning-heavy tasks, tool-augmented workflows, multimodal applications.

Which model is cheaper: Claude 4.5 Sonnet or Claude 4 Sonnet?

Claude 4.5 Sonnet and Claude 4 Sonnet currently share the same published input price of $3.0000 per 1M input tokens.

Which model has the larger context window: Claude 4.5 Sonnet or Claude 4 Sonnet?

Claude 4.5 Sonnet is listed with a context window of 200,000, while Claude 4 Sonnet is listed with 200,000.

How should I evaluate Claude 4.5 Sonnet vs Claude 4 Sonnet for my use case?

This comparison currently includes 12 shared benchmark rows, helping you compare practical performance across overlapping evaluations.