CurlyJSON is a set of free JSON tools for developers that run entirely in your browser. Nothing you paste is uploaded, there's no sign-up, and it keeps working offline.

• A formatter and validator with exact error positions, one-click repair, tree, table and graph views, and 64-bit IDs that are never rounded

• JSON Diff that ignores key order, matches array items by id and can skip timestamps; export Markdown or JSON Patch

• A JSON Schema validator (drafts 4 to 2020-12), plus jq and JSONPath playgrounds

• JSON to TypeScript, Zod, Go, Python, Rust and 22 more languages

• JSON ⇄ CSV and Excel that keeps zip codes and phone numbers as text, plus YAML, XML and TOML

• A JWT decoder, and warnings before you share JSON that contains API keys or passwords

• A free Chrome extension that formats API responses in the tab (also on Microsoft Edge)