Claude Opus 5 or Claude Sonnet 5.5?
Choose Claude Opus 5 when high-quality agents with a lower token price than fable is the closer match. Choose Claude Sonnet 5.5 when full-stack software development, automated ui testing and production agent workflows matters more. Test both on the same real tasks before moving a production workflow.
High-quality agents with a lower token price than Fable
Full-stack software development, automated UI testing and production agent workflows
Claude Opus 5
Anthropic model for complex agentic coding and professional work.
Official specification ↗Claude Sonnet 5.5
Anthropic's workhorse model with enhanced computer use and sub-second token generation.
Official specification ↗Side-by-side comparison
| Category | Claude Opus 5 | Claude Sonnet 5.5 |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Type | Model · Reasoning model | Model · Balanced reasoning model |
| Pricing summary | $5 input, $0.50 cache read and $25 output per 1M tokens | $2 input, $0.20 cache read and $10 output per 1M tokens |
| Input price | $5 / 1M tokens | $2 / 1M tokens |
| Cached input | $0.50 / 1M tokens | $0.20 / 1M tokens |
| Output price | $25 / 1M tokens | $10 / 1M tokens |
| Context window | 1M tokens | 500K tokens |
| Maximum output | 128K tokens | 128K tokens |
| Knowledge cutoff | May 2026 | August 2026 |
| Reasoning | Adaptive; high default effort | Adaptive thinking with custom effort |
| Relative speed | Moderate; optional Fast mode at higher price | High throughput |
| Input modalities | Text and image | Text and image |
| Output modalities | Text | Text |
| Tools and integrations | Claude API tool use, computer use and agent workflows | Claude API tool use, desktop computer use, Claude Code |
| API / access | Claude Messages API | Claude Messages API |
| Best fit | High-quality agents with a lower token price than Fable | Full-stack software development, automated UI testing and production agent workflows |
| Company | Anthropic | Anthropic |
| Product category | Model · Reasoning model | Model · Balanced reasoning model |
| Current pricing note | $5 input, $0.50 cache read and $25 output per 1M tokens | $2 input, $0.20 cache read and $10 output per 1M tokens |
| Best suited to | High-quality agents with a lower token price than Fable | Full-stack software development, automated UI testing and production agent workflows |
| Key capabilities | Complex agent work; Coding; Adaptive thinking; Optional Fast mode | Sub-second latency; Enhanced desktop computer use; 500K context; Claude Code default |
| Last verified | 2026-09-08 | 2026-10-15 |
| Official product source | https://www.anthropic.com/news/claude-opus-5 | https://platform.claude.com/docs/en/models/sonnet-5-5/overview |
How we reached this verdict
We looked at the things that affect everyday use: what each product can do, how its plans are structured, where it fits into your existing workflow, and what the provider currently documents. Benchmark results are useful context, but they are not a universal winner score because test settings and tools vary.
Common questions
Claude Opus 5 or Claude Sonnet 5.5: which should I choose?
Choose Claude Opus 5 for high-quality agents with a lower token price than fable. Choose Claude Sonnet 5.5 for full-stack software development, automated ui testing and production agent workflows. Validate the decision with your own prompts and total task cost.
Is Claude Opus 5 cheaper than Claude Sonnet 5.5?
Pricing units can differ. Claude Opus 5: $5 input, $0.50 cache read and $25 output per 1M tokens. Claude Sonnet 5.5: $2 input, $0.20 cache read and $10 output per 1M tokens. Check tool charges, plan limits, caching and long-context rules before comparing totals.
Which is better for coding and agent work?
Capability depends on the selected product surface, tools and harness. Claude Opus 5 is positioned for high-quality agents with a lower token price than fable; Claude Sonnet 5.5 is positioned for full-stack software development, automated ui testing and production agent workflows. Run the same repository task on both.
How do their context windows compare?
Claude Opus 5 lists 1M tokens; Claude Sonnet 5.5 lists 500K tokens. A larger limit does not by itself guarantee better retrieval or lower cost.
Official sources
Use these provider pages to confirm current features, pricing and availability.
AI tools change quickly. We checked this page on 2026-09-08. Before you subscribe, confirm the latest price, regional availability and usage limits on the provider website.