Web & API

HTML, CSS, requests and responses. Build a header, read a payload, see what a page tells a crawler.

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APIs & HTTP16 Network16 Feeds & structured data15 CSS13 SEO & meta12 HTML12 Web security8

All tools in Web & API

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Combine entries from two JSON feeds, deduplicate by ID/link

Feeds & structured data

Strip tags and extract readable text from HTML

HTTP Header Parser

Paste raw headers and get structured JSON with header count

Sitemap Validator

Check sitemap.xml structure, URL entries

SRI Hash Generator

Generate Subresource Integrity hashes for scripts and stylesheets

Break down Amazon Resource Names into partition, service, region

CSS Border Radius Generator

Create rounded corners with per-corner control

Microdata Extractor

Paste HTML and extract itemscope, itemtype

Feeds & structured data

HTML Table Generator

Create styled HTML tables

MAC Address Lookup

Enter a MAC address and get the vendor/manufacturer, OUI prefix

Canonical URL Builder

Generate canonical link tags to prevent duplicate content issues

Security Headers Check

Audit HTTP response headers for OWASP security best practices

GraphQL Schema Viewer

Format and display GraphQL SDL definitions with proper indentation

Expand simple SCSS variables and nested selectors into plain CSS

Check RSS XML structure, required elements, and best practices

Feeds & structured data

HTML Entity Decoder

Convert HTML entities back to readable characters

IP Range Calculator

Enter CIDR, dash range, or start/end IPs and get total addresses

Open Graph Generator

Create og: meta tags for rich social media previews on Facebook

Generate HTTP Strict Transport Security headers with Apache, Nginx

GraphQL Schema Generator

Create GraphQL type definitions from JSON data

CSS Gradient Generator

Create linear, radial, and conic gradients with custom color stops

Product Schema Generator

Create Product JSON-LD structured data with offers, brand

Feeds & structured data

HTML List Generator

Create ordered or unordered HTML lists

IP in CIDR Checker

Enter an IP address and a CIDR range to check if the IP falls within

See how your page appears in Google search results with title length

Configure Cross-Origin Resource Sharing headers with Express, Nginx

API Mock Data Generator

Create realistic mock JSON data from JSON Schema or sample data

CSS Specificity Calculator

Compute specificity scores for CSS selectors and rank them

Paste Atom XML and get structured JSON with feed metadata, entries

Feeds & structured data

Compress HTML by removing whitespace and comments

MIME Type Lookup

Enter a file extension or MIME type string and get the matching

Schema.org Generator

Create structured data markup for articles, products, organizations

Check Content Security Policy headers for syntax errors and security

Combine two OpenAPI specifications into a single unified spec

Compress CSS by removing whitespace, comments

Paste minified JSON-LD and get pretty-printed structured data

Feeds & structured data

Favicon Generator

Create text-based SVG favicons

Configure URL, method, headers, auth

See how your page looks when shared on Facebook and Twitter

Permissions Policy Builder

Control browser feature access for camera, microphone, geolocation

Paste OPML subscription XML and get a structured JSON list of feeds

Feeds & structured data

HTML Playground

Write HTML, CSS, and JavaScript with live preview

robots.txt Validator

Check robots.txt syntax, directives, and crawl rules for errors

Create Content Security Policy headers with directive configuration

Network Address Converter

4 related tools consolidated into one page

Compare two OpenAPI specifications side by side and detect added

Prettify and indent minified CSS with proper spacing

Breadcrumb Generator

Create BreadcrumbList structured data for SEO

Feeds & structured data

Prettify and indent HTML

Subnet Calculator

Enter CIDR notation or IP with subnet mask and get network address

Sitemap Generator

Create sitemap.xml files with change frequency, priority

XSS Filter Tester

Detect cross-site scripting patterns in input strings with severity

CSS Box Shadow Generator

Create drop shadows and inset shadows with customizable offset

Paste RSS XML and get structured JSON with channel metadata

Feeds & structured data

HTML Entity Encoder

Escape special characters as HTML entities

Hreflang Generator

Create hreflang link tags for multilingual and multi-regional SEO

Check CSS for syntax errors, mismatched braces, and common issues

JSON Feed Parser

Paste a JSON Feed 1.1 document and get a validated

Feeds & structured data

HTML Attribute Remover

Strip inline styles, event handlers, and data attributes from HTML

Twitter Card Generator

Create summary, large image, app

OpenAPI Mock Generator

Create realistic mock JSON responses from OpenAPI specification

CSS Grid Generator

Build grid layouts with configurable columns, rows, gaps

Create valid RSS 2.0 XML feeds with items, categories

Feeds & structured data

Check HTML structure for errors and warnings

Meta Tag Generator

Create essential meta tags for SEO, viewport, charset

CSS Flexbox Generator

Build flex layouts with configurable direction, alignment, wrapping

FAQ Schema Generator

Create FAQPage JSON-LD structured data for Google rich results

Feeds & structured data

IPv6 Compressor

Enter a full or partial IPv6 address and get the shortest compressed

robots.txt Generator

Create crawler directives with disallow paths, sitemap URL

Rich Snippet Preview

Paste JSON-LD and see how the structured data could appear as a search result

Feeds & structured data

Enter an IPv4 or IPv6 address and get version

Cloud Resource Namer

Create properly formatted resource names for AWS, GCP, and Azure

Create valid Atom 1.0 XML feeds with entries, authors, and metadata

Feeds & structured data

CIDR Calculator

Enter CIDR notation and get network address, broadcast, subnet mask

Schema.org Validator

Paste JSON-LD and check for missing required fields, invalid dates

Feeds & structured data

Paste HTTP Archive JSON and get request statistics

OpenAPI Validator

Check OpenAPI and Swagger specifications for structural errors

HTTP Status Reference

Get the meaning, category, and RFC spec for status code 429

HTTP Request Builder

Construct HTTP requests in fetch, cURL, HTTPie

Enter a compressed IPv6 address and get the full 8-group notation

OpenAPI Formatter

Pretty-print and format OpenAPI specification JSON with consistent

HTTP Headers Reference

Browse 40+ standard headers by category (request, response

Webhook cURL Generator

Create ready-to-use cURL commands for testing webhooks with custom payloads, headers and content types

.gitignore Generator

Create .gitignore files for Node.js, Python, Java, Go, Rust, Ruby

OpenAPI Splitter

Break a large OpenAPI specification into smaller specs grouped

API Response Formatter

Pretty-print JSON and XML API responses with configurable indentation and optional key sorting

Display OpenAPI and Swagger specifications in a human-readable

90s Website Maker

Generate a self-contained retro homepage with safe escaped text

Bandwidth Calculator

Calculate transfer time from file size and line speed including byte-to-bit conversion

CSS Button Generator

Generate button HTML and CSS from colors, spacing and radius settings

CSS Animation Generator

Generate a two-keyframe CSS animation with duration and easing controls

Glassmorphism Generator

Generate a frosted-glass CSS panel using alpha color and backdrop blur