Network Tools - API Testing / HTTP / URL / IP Calculator
18 toolsOnline network tools: HTTP API tester, URL parser, User-Agent parser, CIDR calculator, subnet calculator, regex tester.
API & HTTP4
API Tester
Online API tester: GET/POST/PUT/DELETE/PATCH with custom Headers/Body, 30s timeout with cancel. Postman alternative.
HAR Viewer
Online HAR viewer: open .har files exported from browser DevTools — requests grouped by domain, seven-segment timing waterfalls, status distribution, slowest/largest request spotting. Fully local analysis, captures never leave your browser.
HTTP Method Cheatsheet
GET vs POST explained: safety, idempotency, caching, body semantics and when to use each HTTP method, with a complete request-method cheatsheet.
HTTP Status Codes Reference
Complete HTTP status code reference: all 1xx/2xx/3xx/4xx/5xx codes with names, descriptions, and use cases. Searchable and filterable, links to MDN docs.
URL & UA Parsing10
URL Parser & Builder
Free online URL parser tool that breaks down protocol/domain/path/params/hash with visual parameter editing and real-time two-way sync
URL Parameter Parser
Free online URL parameter parser. Quickly parse and edit URL query parameters with add/delete/edit support.
User-Agent Parser
Free online User-Agent parser tool. One-click detection of browser, operating system, device type, vendor, model, and more. Supports bot/crawler detection, mobile/desktop identification, and all major browsers.
Meta Tag Pixel Checker
Online tool to check the pixel width of Title and Description meta tags. Simulates Google SERP preview to avoid truncation.
Open Graph Previewer
Online Open Graph previewer. Enter OG tag content and preview how your page looks when shared on Facebook, Twitter, and LinkedIn.
Sitemap Generator
Free online sitemap generator. Enter a list of URLs and generate a standard XML sitemap with changefreq and priority options.
robots.txt Generator
Free online robots.txt generator. Configure User-agent and Allow/Disallow rules to generate a standard robots.txt file.
AI Crawler Robots Generator
Generate robots.txt rules for popular AI crawlers (GPTBot, ClaudeBot, CCBot, and more): allow or block per bot with one-click presets, live preview, and copy.
llms.txt Generator
Visually build llms.txt (the site guide file for LLM crawlers): tiered sections, bulk link import, and a built-in linter. Generated locally, downloadable.
IDN Converter
Free online IDN/punycode converter: Unicode domains to xn-- ASCII and back. Forward via WHATWG URL, reverse per RFC 3492. Batch support, useful for anti-phishing checks.
IP & Subnet2
CIDR Calculator
Online IPv4 CIDR calculator: input IP/prefix (e.g., 192.168.1.0/24) to calculate network address, broadcast address, subnet mask, host range, and total hosts. Essential for network engineers.
Subnet Calculator
Free online IP subnet calculator. Supports CIDR calculation, subnet division, network and broadcast address computation.