Claude Sonnet 5 just launchedTry Anthropic's new model on Felo AI
Anthropic released Claude Sonnet 5 on June 30, 2026. Try the new agentic model on Felo AI today.
Why Sonnet 5 matters
Sonnet 5 is built for work that does not stop at one chat answer. It plans, uses tools, works through code and documents, and keeps moving across multi-step tasks at a lower price point than Opus-class models.
The most agentic Sonnet yet
Anthropic describes Sonnet 5 as its most agentic Sonnet model. It can make plans, use tools such as browsers and terminals, and run more autonomously on work that previously required larger models.
Coding that follows through
Use Sonnet 5 for repository-level coding help, debugging, test writing, refactoring, and code review. Early feedback cited stronger follow-through on messy technical contexts and multi-step software engineering work.
Better search and computer-use workflows
Sonnet 5 improves over Sonnet 4.6 on agentic search and computer-use evaluations. It gives teams more room to balance effort level, answer quality, and task cost.
Opus-like performance at a lower price
Sonnet 5 narrows the gap with Opus 4.8 on several benchmarks while launching at lower API pricing. It is a practical default for teams that need strong execution without using the most expensive model for every task.
Sonnet 5 vs Sonnet 4.6 vs Opus 4.8
Sonnet 5 is not just a small Sonnet update. It moves closer to Opus 4.8 on agentic coding, computer use, reasoning, and knowledge work, while staying positioned as the everyday model for high-frequency professional workflows.
Built for agentic work
Use Sonnet 5 when the task has moving parts: tools, source material, code, files, constraints, partial results, and decisions that need to stay consistent across turns.
Planning
Ask Sonnet 5 to break work into steps, choose a path, track constraints, and revise when new information appears.
Tool use
Sonnet 5 is designed for workflows that involve browsers, terminals, code execution, file context, and other tools.
Coding
Use it for debugging, reproducing issues, writing tests, reviewing pull requests, and explaining tradeoffs in existing codebases.
Research
Combine Sonnet 5 with Felo Search to compare sources, extract decisions, and turn scattered information into a clear answer.
Knowledge work
Use it for briefs, reports, policy analysis, legal-style research, product planning, and document-heavy professional work.
Safety
Anthropic reports lower hallucination and sycophancy rates than Sonnet 4.6, plus better resistance to malicious requests and prompt-injection hijack attempts.
What to use Sonnet 5 for on Felo
Start with work where stronger model behavior changes the outcome: code that has to run, research that must be checked, and tasks that need a model to keep going without losing the plan.
Agentic coding
Ask Sonnet 5 to investigate bugs, write reproducing tests, propose fixes, review changes, and explain why an approach works.
Source-backed AI search
Use Felo Search with Sonnet 5 to answer complex questions, compare evidence, and keep citations close to the reasoning.
Browser and terminal workflows
Test prompts that involve multi-step browser or terminal-style tasks, where the model needs to choose actions and recover from partial failures.
Long research packs
Bring reports, product docs, meeting notes, technical references, or market research and ask for structured decisions.
Professional automation
Draft launch messages, update business records, summarize client context, or prepare workflows that need reliable follow-through.
Model evaluation
Compare Sonnet 5 against Opus, GPT, Gemini, and other models in Felo before choosing the best model for your actual work.
Two ways to try Sonnet 5 on Felo
Felo LLM Playground
Use the Felo LLM Playground to test Sonnet 5 with your own prompts. Compare effort, answer quality, coding behavior, and style before adding it to a workflow.
Open PlaygroundFrequently Asked Questions
Claude Sonnet 5 is Anthropic's newest Sonnet model, released on June 30, 2026. Anthropic positions it as the most agentic Sonnet model yet, built for coding, tool use, browser and terminal workflows, planning, and professional knowledge work.
Try Claude Sonnet 5 on Felo AI
Use Sonnet 5 for agentic coding, AI search, browser and terminal workflows, research, and long-context knowledge work.
Try Sonnet 5 on FeloOpens Felo AI Search with Sonnet 5 selected where available