What is Claude Sonnet 5?
Anthropic released Claude Sonnet 5 on June 30, 2026. It sits below Claude Opus in Anthropic's lineup but is meant to be the everyday workhorse: strong at coding, careful with instructions, and noticeably good at writing that reads like a person wrote it.
Sonnet 5 supports adaptive thinking with selectable effort, a 1-million-token context window, and text, image and file inputs. Through the API it costs $2 per million input tokens and $10 per million output tokens, the same list price as OpenAI's GPT-6 Sol.
Claude Sonnet 5 specs and pricing
| Made by | Anthropic |
| Released | June 30, 2026 |
| API model ID | claude-sonnet-5 |
| Context window | 1M tokens |
| Inputs | Text, images and files |
| API price | $2 input / $10 output per 1M tokens |
| In AimiChat | Balanced quality · Aimi+ ($15/month) |
API prices are what developers pay Anthropic directly. In AimiChat you pay a flat plan price instead and do not need your own API key. Limits per message and per day depend on your plan.
What Claude Sonnet 5 is good at
- Writing that needs little editing. Reports, articles, cover letters and long emails where structure and tone matter.
- Following detailed instructions. Prompts with many constraints, formats or style rules that must all be respected at once.
- Coding. Explaining unfamiliar code, writing functions with tests, and debugging with a clear account of what changed.
- Working with documents. Reading long PDFs, contracts or research papers and answering precise questions about them.
When to use a different model
- The hardest problems. For long, high-stakes reasoning or large codebase changes, Claude Opus 5.5 is the stronger choice.
- Quick one-line answers. If you only need a fast definition or rewrite, GPT-6 Luna on the Free plan is quicker and uses fewer credits.
Prompts to try with Claude Sonnet 5
- Here is my rough draft. Keep my voice, cut filler, and flag any sentence that makes a claim I have not supported.
- Review this function for bugs and edge cases, then rewrite it with tests.
- Read this contract and list every obligation, deadline and penalty, with the clause each one comes from.
How to use Claude Sonnet 5 in AimiChat
- Open AimiChat and sign in on the Aimi+ plan or higher (see plans).
- Choose the Balanced quality in the model menu next to the message box.
- Send your message. You can switch quality in the same chat at any time, so you can start with a faster model and move up when a question needs more depth.
Compare Claude Sonnet 5
- Claude Sonnet 5 vs GPT-6 Sol: when GPT-6 Sol is the better pick.
- Claude Opus 5.5 vs Claude Sonnet 5: when Claude Opus 5.5 is the better pick.
- Claude Sonnet 5 vs GPT-6 Luna: when GPT-6 Luna is the better pick.
See every model in AimiChat side by side.
Claude Sonnet 5 FAQ
Which AimiChat plan includes Claude Sonnet 5?
Claude Sonnet 5 powers the Balanced quality, included from the Aimi+ plan ($15/month). Aimi Ultra and Aimi Genius include it too.
How big is Claude Sonnet 5's context window?
Anthropic's API lists 1 million tokens. The amount you can use in a single AimiChat message depends on your plan.
Is Claude Sonnet 5 better than GPT-6 Sol?
They cost the same through the API and are close overall. Sonnet 5 tends to be the better writer and instruction follower; GPT-6 Sol is aimed at demanding reasoning and agentic coding. See the full comparison for details.
Is Claude Sonnet 5.5 available?
Not yet. Anthropic has said Sonnet 5.5 will follow Opus 5.5 in the coming weeks.
Sources
Specifications and prices come from the model makers and API listings below. Benchmark figures are reported by the company that made the model and are not independent tests.