Free Browser Tools

HTTP Status Code Explorer

Interactive reference for 40+ status codes

Client-Side Port Scanner

Detect open ports on localhost

Browser Network Capabilities Tester

Online status, connection type, downlink estimate

Ping & Latency Visualizer

Graph live latency and network stability in your browser.

Subnet & CIDR Calculator

Compute network, broadcast, range and host count for any IPv4 CIDR.

HAR (HTTP Archive) Viewer

Parse .har files locally to inspect load times and payloads.

GraphQL Schema Introspector

Parse SDL, browse types and generate query skeletons.

DNS Propagation Emulator

Simulate resolver caches and TTL countdown over 24 hours.

HTTP Header Builder & Auditor

Build raw requests, parse responses, audit security headers.

WebRTC Signaling Playground

Copy-paste SDP to open a direct data channel between tabs.

WebSocket Tester & Frame Logger

Connect to ws/wss endpoints, log frames and measure latency.

Node.js

package.json Security Auditor

Audit a package.json for risky or outdated dependencies.

Node.js

.env Security Validator

Validate .env files for placeholder secrets and missing values.

Node.js

Express.js Route Mapper

Parse Express routing code into a visual endpoint map.

Performance

Framework Bundle Budget Calculator

Estimate load times from bundle sizes across network speeds.

Core Web Vitals Predictor

Rate TTFB, LCP, CLS and INP against Google thresholds.

Image Compression Previewer

Compare original vs compressed size and quality side by side.

CSS Selector Performance Analyzer

Rank CSS selectors by rendering cost and flag risky rules.

Font Payload Optimizer

Inspect glyph coverage and estimate subsetting savings.

SEO

llm.txt Compliance Checker

Validate AI scraper instructions

robots.txt Rules Parser

Test URL access rules for any user-agent

Sitemap XML Visualizer

Parse sitemaps, filter, search, export CSV

Meta Tag Analyzer

Analyze title, meta, OpenGraph tags

SERP Preview Generator

Preview Google search results desktop + mobile

Social Card Preview

OG card previews and a 1200x630 image generator

Schema Markup Generator

Build and validate JSON-LD structured data

robots.txt & llms.txt Generator

Generate robots, llms and security files

Keyword Density & Content Analyzer

Count words, reading time and top keyword phrases.

Structured Data (Schema.org) Validator

Validate JSON-LD schema syntax locally.

Redirect / Regex Path Mapper

Test URL rewrite rules and regex mappings in real time.

Security

security.txt Auditor

Validate security.txt per RFC 9116

Password Breach Checker

Check passwords against HIBP with k-anonymity

CSP & Security Headers Generator

Build Content-Security-Policy and header sets

WordPress Salt Generator

Generate wp-config keys and salts

WordPress Hardening Generator

wp-config.php and .htaccess snippets

chmod Permission Calculator

Convert octal modes and rwx permissions

JWT Decoder

Decode JWT headers, claims and expiry

Hash Generator

MD5, SHA-1, SHA-256 and SHA-512 digests

Client-Side Password Vault & Generator

Generate strong passwords and encrypt a credential list locally with a master password.

SSL/TLS Certificate Decoder

Decode a PEM certificate to inspect its size and SHA-256 fingerprint.

Content Security Policy (CSP) Builder

Build and evaluate a CSP header interactively.

CORS Preflight Simulation Sandbox

Simulate CORS preflight requests and headers.

Web Crypto Key Pair Generator

Generate RSA or ECDSA key pairs and export JWK/PEM locally.

Bcrypt / Argon2 Playground

Hash passwords with bcrypt or Argon2id via WebAssembly.

BIP39 Mnemonic Converter

Generate seed phrases and derive BTC/ETH keys offline.

Steganography Encoder / Decoder

Hide and extract text in PNG pixel data locally.

JWT Signature Verifier

Verify RS/PS/ES/HS JWT signatures with a public key locally.

Utility

Scope Estimator

Size your management needs in 30 seconds

Password Generator

Strong passwords, generated locally

Image Converter & Compressor

Resize and convert to WebP, AVIF or JPEG

Base64, URL & HTML Encoder

Encode and decode text locally

Crontab Generator & Explainer

Build and decode cron schedules

Log Parser & Anonymizer

Parse server logs, filter by level, anonymize IPs/emails.

CSV to JSON/XML Converter

Parse CSV and export JSON, XML or SQL inserts.

Base64 Image Encoder/Decoder

Convert images to Base64 data URIs and back.

Local/Session Storage & Cookie Inspector

Inspect everything stored in your browser for this origin.

Unix Timestamp & Epoch Converter

Convert between Unix timestamps and human dates.

UUID / ULID Bulk Generator

Generate thousands of UUIDs or ULIDs locally.

Diff Checker & Text Merge

Compare two text blocks line by line.

Base Converter (Binary/Octal/Decimal/Hex/Base64)

Convert numbers between bases.

Cron Expression Explainer

Explain a crontab expression in plain English.

Regex Visualizer & Match Tester

Highlight matches, capture groups, timings and substitutions.

JSON Schema Generator & Validator

Infer JSON Schema from data and validate documents.

SQL Formatter & Syntax Checker

Format SQL with keywords, indentation and balance checks.