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Claude Sonnet 4.5 vs Claude Opus 4.8

Claude Opus 4.8: 58.3% average across five Vision Evals tasks (#40 of 65 models). We have not run Claude Sonnet 4.5 through Roboflow's Vision Evals, so there is no head-to-head score. Run both on your own image below.

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AnthropicClaude Sonnet 4.5
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AnthropicClaude Opus 4.8
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Claude Sonnet 4.5 vs Claude Opus 4.8 Comparison Table

Evals updated October 26, 2026Pricing updated November 5, 2026

PropertyClaude Sonnet 4.5Claude Opus 4.8
OrganizationAnthropicAnthropic
Categoryclosedclosed
Modalitymultimodalmultimodal
Release DateSep 2025May 2026
Context Window200K1.0M
ParametersUnknownUnknown
LicenseProprietaryProprietary
Commercial usecommercial use per vendor termscommercial use per vendor terms
Pricing per 1M tokens
Input $/1M$3.00$5.00
Output $/1M$15.00$25.00
Vision Tasks
Both support 10 more tasks
Model Features
Both support 3 more features
Vision Evalsground-truth scores across 5 vision tasks, pooled at low effort
OverallNot evaluated
58.3%
Avg cost / sample–$0.021
Avg speed / sample–7.66s
By task
Object Detection–
38.6%
$0.026
Counting–
54.0%
$0.0076
Identification–
84.4%
$0.0067
OCR (low)–
61.5%
$0.025
by category
Single value
53.0%
Transcription
70.8%
Structured JSON
82.4%
Text localization
24.2%
OCR (high)–
62.1%
$0.038
by category
Single value
54.8%
Transcription
67.0%
Structured JSON
83.5%
Text localization
23.6%
Reasoning (low)–
53.0%
$0.0078
Reasoning (high)–
52.3%
$0.0078

Claude Sonnet 4.5 vs Claude Opus 4.8: Overview

Claude Sonnet 4.5

Claude Sonnet 4.5, released by Anthropic in September 2025, is the company’s most advanced Sonnet-series model, built for high-performance reasoning, coding, and long-horizon agentic workflows. It is a multimodal system that accepts both text and images, with a 200,000-token context window designed for handling large documents and extended interactions. Anthropic highlights its improvements in reliability, reduced sycophancy, and alignment, making it suitable for sustained enterprise use.

It introduces infrastructure features such as a memory tool (beta), checkpointing for Claude Code, parallel tool use, and tighter integration with VS Code. Compared to Opus, which targets broader reasoning, Sonnet 4.5 is optimized for structured, long-duration tasks. Positioned against leading offerings from OpenAI and Google, it is aimed at enterprise automation, software engineering, and research-intensive applications.

Claude Opus 4.8

Claude Opus 4.8 is Anthropic's most capable generally available large language model, released on May 28, 2026 as an incremental upgrade to Claude Opus 4.7. The model accepts text and image inputs and produces text outputs, with a 1 million token context window on the Claude API, Amazon Bedrock, and Google Cloud Vertex AI (200k tokens on Microsoft Foundry) and up to 128k max output tokens. It uses adaptive thinking and supports adjustable effort tiers — high by default, with extra and max tiers available for more demanding tasks. A fast mode operates at approximately 2.5x standard speed. The model is described by Anthropic as a hybrid reasoning model designed for advanced coding, agentic workflows, long-context reasoning, and professional knowledge work.

Key behavioral improvements over Opus 4.7 include substantially reduced rates of unreported code flaws, improved honesty in self-assessment, and better tool-calling reliability. On Anthropic's Super-Agent benchmark, Opus 4.8 completes every case end-to-end, and it scores 84% on Online-Mind2Web for computer-use and browser-agent tasks. Alongside the model, Anthropic launched Dynamic Workflows in Claude Code (research preview), which enables Claude to orchestrate hundreds of parallel subagents for codebase-scale tasks such as large migrations. The Messages API was also updated to accept mid-task system messages without breaking prompt caching, improving support for long-running agentic pipelines.