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HeyUtils: 306 free developer tools for everyday debugging
Explore 306 tools across 41 categories, with practical workflows for data conversion, API debugging, logs and domains, plus clear guidance on local and network processing.
HeyUtils has grown from a single CSV converter into a collection of 306 published tools across 41 categories, available in nine languages as of September 24, 2026. You can format data, inspect requests, read certificates, work through logs and prepare configuration files without creating an account.
The tool directory is the starting point. Search by the task you need to finish, browse a category, or bookmark frequently used pages in your browser. The catalog now covers data formats, text and encoding, dates and numbers, APIs and security, networking, DevOps, frontend development, and AI helpers.
Four ways to use the collection
Turn an export into a typed data sample
Start with CSV to JSON to convert a spreadsheet export. Inspect the output in the JSON formatter, then generate a starting type definition with JSON to TypeScript.
Check identifiers, leading zeros and optional fields before integrating the result. Types inferred from one sample describe that sample; they cannot establish every shape your API might return.
Follow an API request from command to response
Use the cURL converter to translate a command into code. The HTTP client lets you send a browser request, the JWT debugger helps inspect token contents, and the JSON formatter makes response bodies easier to read.
Browser requests still depend on the destination’s CORS policy. Reading a token’s claims also does not, by itself, verify its signature or make it safe to trust.
Make a production error easier to investigate
Filter a sample in the log viewer, organize a pasted trace with the stack trace formatter, and use the source map viewer when you have the matching map. Each step answers a different question: what happened, where it appeared, and which original source location it maps to.
Check a domain change
Inspect records with DNS lookup, prepare email policy records with the SPF builder and DMARC builder, then inspect published records with the email DNS checker. After certificate renewal, the SSL checker can retrieve a public certificate through NetworkCalc and show its dates and DNS names.
Know where each input goes
Many converters, formatters and file inspectors process inputs locally in your browser. Network tools need a destination or an external provider: DNS queries leave the browser, HTTP requests go to the selected endpoint, and SSL lookups send the hostname and port directly to NetworkCalc. The SSL checker does not validate trust chains, revocation or TLS version support.
The webhook tester is another explicit exception: it stores received requests temporarily so you can inspect them. Inboxes expire 30 minutes after creation, with limits of 50 events and 64 KiB of body data per event. Sensitive headers are redacted, but query strings and bodies are not automatically scrubbed. Use test data and read the privacy policy for details.
Start with the task in front of you
You do not need to learn the whole catalog. Pick the tool that solves your immediate problem, check its examples and limits, and export the result when it is ready. If you find an incorrect result or a missing workflow, use the feedback link on the page and include a small, non-sensitive example that reproduces it.
Browse all 306 tools and build your own set of everyday shortcuts.