Best Network & IP Tools

A hand-checked list of the best free network & ip tools for developers. Every tool runs in your browser — no upload, no login, no API key.

25 tools

Subnet Calculator

Network & IP

Calculate network, broadcast, host range, and mask from an IPv4 CIDR.

CIDR Range Expander

Network & IP

Expand a CIDR block into individual addresses, or compress a range into CIDR blocks.

IP Converter

Network & IP

Convert IPv4 to decimal/hex/binary, and expand or compress IPv6.

URL Parser

Network & IP

Break a URL into protocol, host, port, path, query, and hash.

Query String Converter

Network & IP

Convert between URL query strings and JSON, with nested bracket support.

User Agent Parser

Network & IP

Parse a user-agent string into browser, engine, OS, and device type.

HTTP Status Codes

Network & IP

Searchable reference of HTTP status codes with meaning and usage guidance.

MAC Address Tools

Network & IP

Validate and reformat MAC addresses, and look up the OUI vendor prefix.

Port Number Lookup

Network & IP

Search well-known TCP/UDP ports and their services.

HTTP Headers Explainer

Network & IP

Look up common HTTP headers and explain pasted raw headers.

DNS Record Types Reference

Network & IP

Searchable reference of DNS record types with examples.

IPv6 Expander/Compressor

Network & IP

Expand an IPv6 address to full form or compress it to shorthand.

MIME Type Lookup

Network & IP

Search file extensions and their MIME types.

HTTP Cache Header Planner

Network & IP

Plan Cache-Control, ETag and max-age headers for any asset type.

IP & CIDR List Validator

Network & IP

Validate and normalise lists of IPv4, IPv6 and CIDR entries offline.

OAuth URL Builder

Network & IP

Build OAuth 2.0 / OIDC authorization URLs with PKCE support.

Cookie Attribute Analyzer

Network & IP

Parse Set-Cookie headers and flag security issues.

HTTP Header Comparator

Network & IP

Diff two sets of HTTP headers, case-insensitively.

DNS Lookup

Network & IP

Query A, AAAA, MX, TXT, NS, CNAME and other DNS records for any domain.

Punycode / IDN Converter

Network & IP

Convert internationalised domain names to punycode and back.

Web Performance Analyzer

Network & IP

Measure TTFB, page size, compression, caching and resource counts for any URL.

URL Redirect Chain Analyzer

Network & IP

Trace every redirect hop with status codes, timing and the final URL.

Webpage Resource Extractor

Network & IP

List every script, stylesheet, image, font and media file a page loads.

Bulk URL Status Checker

Network & IP

Check HTTP status codes and redirects for many URLs at once.

Bulk File Downloader

Network & IP

Paste many URLs and save every file one by one, with a pause between downloads.