Online Tools
Handy Programming tools that run entirely in your browser — nothing is uploaded.
JSON & Data
JSON Formatter
Format, minify and validate JSON with parse error hints.
JSON Viewer
Render JSON as a collapsible, type-colored tree for exploring deeply nested data.
JSON to CSV
Convert an array of objects to CSV, flattening nested fields and escaping delimiters and quotes.
JSON Diff
Recursively compare two JSON documents and list added, removed and changed paths.
Encoding
Base64 Converter
Convert text to and from Base64 with full UTF-8 and URL-safe support.
File to Base64
Convert small local files such as images or fonts into Base64 / Data URI. Nothing is uploaded.
URL Encoder / Decoder
Percent-encode or decode URLs and query values, with encodeURI and encodeURIComponent modes.
HTML Entities
Escape or unescape HTML entities, including converting non-ASCII characters to numeric entities.
Text ↔ Binary
Convert text to and from 8-bit binary using UTF-8, with full support for CJK and emoji.
Integer Base Converter
Convert integers between binary, octal, decimal, hex and any base from 2 to 36, including big integers.
Hash & Crypto
Hash Generator
Compute SHA-1 / SHA-256 / SHA-384 / SHA-512 digests with Web Crypto. Text never leaves your browser.
HMAC Generator
Compute HMAC-SHA1/256/384/512 signatures with Web Crypto, in hex and Base64, entirely in your browser.
JWT Parser
Decode JWT header and payload locally, including expiry hints. No upload and no signature verification.
TOTP Generator
Generate 6/8-digit TOTP codes from a Base32 secret with a live countdown, for debugging two-factor login.
IDs & Generators
UUID Generator
Generate UUID v4 in bulk, with uppercase and no-dash options.
ULID Generator
Generate time-sortable ULIDs (Crockford Base32, 26 chars); values stay monotonic within the same millisecond, ready for primary keys.
Token Generator
Generate random tokens with a chosen length and charset using Web Crypto, with unbiased sampling.
Lorem Ipsum Generator
Generate placeholder Lorem Ipsum text by paragraph, sentence or word count.
Network
IPv4 Subnet Calculator
Compute network and broadcast address, netmask, wildcard, usable host range and host count from CIDR.
IPv4 Address Converter
Convert dotted IPv4 addresses to and from integer, hex and binary forms for log and database debugging.
IPv4 Range Expander
Split an IP range into the minimal list of CIDR blocks for firewall and routing rules.
Random Port Generator
Generate unique random port numbers within a range for local debugging setups.