Developer topic guide
Network tools
DNS, WHOIS, SSL, HTTP headers, and cURL helpers for quick network debugging in your browser.
Topic guides
Browse focused guides that compare related tools and link to the best starting point for your task.
- JSON toolsFormat, validate, compare, and convert JSON with free developer utilities in your browser.
- JWT toolsDecode, encode, and generate JSON Web Tokens in your browser with Utilnivo JWT tools.
- Encoding toolsBase64, URL, and HTML encoding utilities for developers — free and browser-based.
- FormattersFormat and minify HTML, CSS, JavaScript, SQL, XML, YAML, and Markdown in your browser.
- Network toolsDNS, WHOIS, SSL, HTTP headers, and cURL helpers for quick network debugging in your browser.
- Security toolsHash, checksum, and regex utilities for developers — free browser-based security helpers.
- UUID toolsGenerate and decode UUIDs with free developer tools in your browser.
Tools in this guide
Overview
Network tools query public infrastructure data: DNS records, domain registration summaries, certificate expiry, and response headers. They complement browser DevTools when you need an external vantage point.
Lookups contact third-party services and may be rate-limited. Results can be cached or incomplete for private hosts. Short Link Generator creates redirect URLs when testing campaigns.
Do not use WHOIS or DNS output as sole security proof — combine with SSL Checker and your own monitoring.
How to choose
- Record lookup → DNS Lookup.
- Domain registration → WHOIS Lookup.
- HTTPS cert expiry → SSL Checker.
- Response inspection → HTTP Header Checker (SEO & Webmaster category).
- Request builder → cURL Builder.
Frequently asked questions
Do lookups run on my device only?
Network tools query external services. Your query leaves the browser to reach DNS/WHOIS providers.
Why is WHOIS redacted?
Many registrars hide personal data under privacy services.
Can I test internal hostnames?
Public lookup tools cannot resolve private intranet names.
Related workflows
These multi-step guides chain tools from this category for common jobs.