Developer
Encoders, formatters, generators, and converters for everyday developer tasks — all client-side.
Reading something opaque 19
JWT Decoder and Generator
X.509 Certificate Decoder
CSR Decoder — Inspect a PKCS#10 Certificate Signing Request
Protobuf Decoder
CBOR Decoder & Encoder
Smart Decode (Magic Decoder)
SafeLink Decoder
URL & IP Defanger and Refanger
File Type Detector — Identify Files by Magic Bytes
Hex Dump
Binary Strings Extractor
URL Parser
User-Agent Parser
Unicode Character Inspector
JavaScript Keycode Inspector
Device Info
MAC Address Vendor Lookup
Cron Expression Explainer
3D Tiles Viewer & Georeferencer (move + save tileset.json)
Formatting and checking 15
Generating 19
ID Generator
Password Generator
TOTP / 2FA Code Generator
BIP39 Mnemonic Generator and Validator
Mock Data Generator
QR Code Generator
Barcode Generator
Sitemap.xml Generator — Build a Sitemap From a URL List
robots.txt Generator — Build a Crawler Rules File Online
Meta Tags Generator
HTTP Basic Auth Header Generator & Decoder
JSON Schema Generator
.gitignore Generator
UTM Builder — Campaign URL Tracking Link Generator
Query String Builder
curl Command Builder
IPv6 ULA Generator (RFC 4193)
Markdown Table Generator
Markdown Table of Contents Generator
Converting 22
JSON to CSV & CSV to JSON Converter
JSON to Code
curl to Code Converter
CSV to SQL INSERT Generator
CSV to Markdown Table
.env to JSON Converter
INI to JSON Converter
JSONL to JSON Array Converter
YAML ⇄ JSON Converter
JSON Flatten & Unflatten
Delimiter Converter
Docker Run to Compose
Markdown to HTML
BBCode to HTML Converter
HTML to Text Converter (Strip HTML Tags)
HTML to JSX Converter
SVG to JSX Converter
Unix Timestamp Converter
Discord Timestamp Generator
SQL IN Clause Generator
Line Numberer
Data Extractor
Encoding and escaping 6
Keys, hashes and encryption 11
Hash & HMAC Generator (MD5, SHA)
bcrypt Hash Generator & Password Verifier
Argon2 Password Hash Generator & Verifier
Password Strength & Entropy Checker
Shannon Entropy Calculator
Text Encrypt & Decrypt (AES)
PGP Encryption Tool
XOR Cipher — Single-Byte Brute Force
RSA Key Pair Generator (2048/4096)
EC / ECDSA Key Pair Generator
JWK to PEM Converter
Addresses, numbers and check digits 13
IP Subnet Calculator (IPv4 CIDR)
IP Address Converter (IPv4 & IPv6)
IP Range to CIDR Converter
Email Normalizer
Phone Number Formatter & Validator
IBAN Validator & Formatter
ISBN Validator (ISBN-10 & ISBN-13)
Luhn Checker & Check Digit Calculator
Bitwise Calculator
Two's Complement Converter (Any Bit Width, Binary & Hex)
Gray Code Converter (Decimal ⇄ Binary ⇄ Gray Code)
Chmod Permission Calculator
Resistor Color Code Calculator
Reference 5
Not sure which tool?
The largest group here, so by job rather than by name. Reading something opaque: decode a JWT, an X.509 certificate, a protobuf message, a data URL, a defanged URL or a safelink; work out what a file actually is from its bytes. Making something correct: format or repair JSON, YAML and XML, test a regex, test an XPath or JSONPath, check a JSON Schema, read a cron expression back in plain words.
Generating: UUIDs and other IDs, passwords, TOTP codes, BIP39 mnemonics, mock data, QR and barcodes, sitemaps, basic-auth headers. Converting: JSON to CSV or to typed code in eight languages, curl to code, timestamps, IP notations, character encodings, text to binary.
Everything here runs in your browser. The JWT decoder does not send your token anywhere; the hash generator hashes locally; the password generator uses your browser's own cryptographic random source. That is the reason to use these rather than the first search result — a token or an internal payload pasted into a server-side tool is a token you have to rotate.