Developer Tools

Encode, decode, format, hash, diff, and inspect data with dedicated tools for everyday development tasks. Pick a category below to get started — everything runs locally in your browser.

Base64 Tools

  • Base64 Encoder

    Convert UTF-8 text or local file bytes to Base64. Choose standard (+/ with padding) or URL-safe (-_ …

  • Base64 Decoder

    Turn Base64 or Base64URL strings into UTF-8 text. Paste an encoded segment and click Run — handy for…

  • Data URI Encoder

    Wrap UTF-8 text in a data: URL with Base64 encoding. Set the MIME type in tool settings (default tex…

  • Data URI Decoder

    Paste a data: URI to extract the MIME type and decoded content. Supports Base64-encoded and percent-…

URL Tools

  • URL Encoder

    Percent-encode text for a query value with encodeURIComponent, or preserve URL separators with encod…

  • URL Decoder

    Paste a URL-encoded value and click Run to decode. + is treated as a space (form-style). Stray % cha…

  • Query String Parser

    Parse query parameters from a full URL or raw query string. Hash fragments (#...) are ignored; semic…

HTML Tools

  • HTML Entity Encoder

    Escape text as HTML entities for safe text display. Minimal mode escapes <, >, &, quotes, and apostr…

  • HTML Entity Decoder

    Convert HTML character entities like &amp; and &lt; back to plain text. This decodes entities in one…

  • HTML Formatter

    Pretty-print HTML with consistent indentation. Improves readability but does not validate or repair …

  • HTML Whitespace Compressor

    Remove HTML comments and extra spacing between tags. Quoted attribute values are preserved; unquoted…

  • HTML to Plain Text

    Extract visible text from HTML. Script, style, and noscript blocks are skipped. Line breaks are adde…

Hex Tools

  • Hex Encoder

    Convert text to hexadecimal (UTF-8 bytes). Outputs a continuous lowercase hex string with no spaces …

  • Hex Decoder

    Decode hexadecimal strings (UTF-8 bytes) back to readable text. Spaces, colons, and 0x prefixes are …

JSON Tools

  • JSON Formatter

    Pretty-print minified JSON with readable indentation, or switch to tree view to explore nested struc…

  • JSON Stringify

    Minify formatted JSON into a compact single-line string. Paste indented JSON and click Run for API r…

  • JSON Syntax Checker

    Check whether JSON is syntactically valid before deploying configs or debugging API responses. Synta…

  • JSON Sort Keys

    Alphabetically sort object keys recursively for stable diffs, cleaner configs, and predictable test …

  • JSON Escape

    Escape quotes, newlines, and special characters so raw text can be embedded in JSON payloads or conf…

  • JSON Unescape

    Convert escaped JSON string values back to readable text. Paste a quoted JSON string literal, or esc…

  • JSON to CSV

    Turn a JSON array of objects into CSV for spreadsheets and data imports. Flatten nested objects firs…

  • CSV to JSON

    Parse CSV with a header row into a JSON array of objects. Paste CSV data and click Run to produce fo…

  • JSON Path Tester

    Run JSONPath queries against JSON data to extract nested values. Paste your JSON, enter a JSONPath e…

  • JSON Schema Check

    Check whether JSON data conforms to a JSON Schema for local debugging. Draft support depends on your…

  • JSON Schema Generator

    Infer a JSON Schema from sample JSON data. All fields present in the sample are marked required — re…

  • JSON Flatten

    Convert nested JSON objects and arrays into a flat key-value map with dot and bracket notation. Root…

  • JSON Unflatten

    Restore nested JSON from flat dot-notation keys. Expects a flat object — keys with dots in original …

  • JSON Merge

    Deep merge two JSON objects. Nested objects merge recursively; arrays from the second object replace…

  • JSON Patch Generator

    Generate an RFC 6902 JSON Patch by comparing two documents. Paste the original JSON as input, add th…

  • JSON to YAML

    Convert JSON documents to YAML. Paste JSON and click Run to generate readable YAML output.

  • YAML to JSON

    Parse YAML into formatted JSON. Multi-document YAML (--- separators) converts to a JSON array. Maxim…

  • JSON to XML

    Convert JSON to XML with a root <root> wrapper element. Round-tripping through XML to JSON will incl…

  • XML to JSON

    Parse XML into formatted JSON. Attributes appear with an @_ prefix; a single child element becomes a…

  • JSON to TypeScript

    Generate TypeScript interfaces from sample JSON. Types reflect only fields in your sample — optional…

  • JSON to Go

    Generate Go struct types from sample JSON. Types reflect only fields in your sample — optional field…

  • NDJSON Lint

    Check each line of NDJSON (JSON Lines) for syntax issues. Trailing blank lines after the last record…

  • JSON Schema to TypeScript

    Convert a JSON Schema document into TypeScript interfaces or types. Review and refine output before …

SQL Tools

  • SQL Formatter

    Pretty-print SQL with consistent indentation and uppercase keywords. Select your dialect, paste a qu…

JavaScript Tools

  • JavaScript Formatter

    Pretty-print plain JavaScript with consistent indentation. TypeScript and JSX are not supported — pa…

  • JavaScript Minifier

    Minify plain JavaScript by removing whitespace and comments only. Variable names are preserved and c…

CSS Tools

  • CSS Formatter

    Pretty-print CSS with consistent indentation. Paste styles and click Run.

  • CSS Whitespace Compressor

    Remove CSS comments and extra spacing between rules. This compresses whitespace only — it does not s…

  • CSS Specificity Calculator

    Enter one or more comma-separated CSS selectors to see approximate specificity scores as (IDs, class…

  • CSS Unit Converter

    Enter a numeric value and choose a conversion mode. Set root or context font size in tool settings (…

XML Tools

  • XML Formatter

    Pretty-print XML with consistent indentation. Re-serializes the document — comments, CDATA sections,…

  • XML Syntax Checker

    Check whether XML is well-formed. Syntax check only — does not validate XSD schemas or guarantee pro…

  • XPath Tester

    Paste XML in Input and enter an XPath expression in Tool Settings. Returns matching nodes or scalar …

TOML Tools

  • TOML Formatter

    Pretty-print TOML configs. Comments are removed and values may be normalized — review output before …

  • TOML Syntax Checker

    Check whether TOML is syntactically valid before committing config changes. Syntax only — Cargo, PEP…

GraphQL Tools

  • GraphQL Formatter

    Format GraphQL queries, mutations, subscriptions, and SDL. Comments are removed — review output befo…

UUID & ID Tools

  • UUID Generator

    Generate cryptographically random UUID v4 values for database primary keys, API request IDs, and dis…

  • UUID Syntax Checker

    Check whether a string is a valid UUID and identify its version (v1, v4, v5, etc.). Accepts hyphenat…

  • ULID Generator

    Create lexicographically sortable ULIDs that embed a millisecond timestamp. Click Run with empty inp…

  • NanoID Generator

    Generate URL-safe NanoIDs for session tokens, short links, and client-side IDs. Click Run with empty…

  • ObjectID Inspector

    Decode a MongoDB ObjectId to see when it was created and its internal hex breakdown. Paste a 24-char…

JWT Tools

  • JWT Decoder

    Paste a JSON Web Token to decode its header and payload, inspect standard claims, and check expirati…

  • JWT Generator

    Create signed JSON Web Tokens from a JSON payload object. Select an HMAC algorithm (HS256/384/512), …

  • JWT Signature Checker

    Inspect a JWT signature and decode claims for debugging. Enter your HMAC secret or RSA public key (P…

  • JWT Claim Editor

    Load an existing JWT or start from scratch. Edit header and payload JSON, enter your signing secret,…

Date & Time Tools

  • Unix Timestamp Converter

    Convert between Unix timestamps (seconds or milliseconds) and readable dates. Paste a timestamp or d…

  • ISO 8601 Parser

    Paste an ISO 8601 date-time string to validate it and see a full breakdown across UTC, local time, a…

  • Time Zone Converter

    Convert a date-time from one IANA time zone to another. Paste a timestamp or date string, select sou…

  • Date Difference Calculator

    Find the duration between two dates. Enter start and end dates on separate lines or separated by |, …

  • Relative Time Calculator

    Add or subtract a duration from a base date. Line 1: base date (or leave empty / type now for curren…

  • Cron Expression Tool

    Parse an existing cron expression or build one field by field. Validate schedules, see human-readabl…

Auth Tools

  • PKCE Generator

    Generate a PKCE code_verifier and code_challenge for OAuth 2.0 authorization flows. S256 is recommen…

  • Basic Auth Generator

    Create a Base64-encoded Basic Auth credential and ready-to-use Authorization header. Enter username …

  • OAuth URL Builder

    Construct an OAuth authorization URL from your provider settings. PKCE parameters are included only …

Hashing Tools

  • Hash Generator

    Compute one or more cryptographic hashes of text or a local binary file. SHA-256 is selected by defa…

  • HMAC Generator

    Compute HMAC signatures for API authentication and webhook verification. The secret key is treated a…

  • BCrypt Generator

    Generate a BCrypt hash from a password. Select a cost factor, enter a password, and click Run — for …

  • Password Entropy Checker

    Analyze password strength with estimated entropy bits and practical suggestions. Paste a password an…

  • Password Generator

    Generate cryptographically random passwords locally in your browser. Each enabled character set is g…

  • AES Encrypt

    Encrypt text with AES-GCM (no PKCS7 padding — GCM accepts any plaintext length). Enter a 128- or 256…

  • AES Decrypt

    Decrypt AES-GCM ciphertext (no PKCS7 padding). Use the same key and IV from encryption. Paste cipher…

Certificate Tools

  • Certificate Decoder

    Paste a PEM-encoded X.509 certificate to inspect metadata. PEM format only — DER/base64 and certific…

IP Tools

  • Subnet Calculator

    Enter an IPv4 address in CIDR notation (e.g. 192.168.1.0/24) and click Run. IPv6 is not supported.

Number Tools

  • Number Base Converter

    Convert integers between supported bases. Negative values use a sign prefix in non-decimal output (n…

Unicode Tools

  • Unicode Converter

    Enter a single character or a code point (U+0041, 0x41, or decimal). Code point mode does not accept…

  • UTF-8 Byte Length

    Count UTF-8 bytes versus JavaScript UTF-16 code units. Emoji and non-ASCII text use more bytes than …

HTTP Tools

  • curl Builder

    Enter a URL and optional method, headers, and body in Tool Settings to generate a curl command.

  • curl to Code

    Paste a curl command to generate JavaScript fetch or Python requests starter code. Review output bef…

  • HTTP Header Parser

    Paste raw HTTP headers with one header per line (Name: Value). Parses locally for debugging.

  • User-Agent Parser

    Paste a User-Agent string to see heuristic browser and OS labels. For debugging only — not authorita…

Env Tools

  • Env File Parser

    Paste .env file contents to list parsed environment variables. Supports quoted values, inline commen…

  • Env File Syntax Checker

    Syntax check only — flags unclosed quotes, invalid keys, and duplicate variables. Does not verify re…

  • Env to JSON

    Paste .env contents and click Run to produce a JSON object of key-value pairs.

SemVer Tools

  • SemVer Compare

    Enter the first version in Input and the second in Tool Settings, then click Run.

  • SemVer Parser

    Paste a semantic version string and click Run to inspect its components. Requires MAJOR.MINOR.PATCH …

  • SemVer Bump

    Enter a version and select bump type in Tool Settings, then click Run.

Regex Tools

  • Regex Tester

    Test regular expressions against sample text. Match finds patterns with positions, Replace substitut…

  • Glob Pattern Tester

    Enter a glob pattern in Tool Settings and paste sample paths (one per line) in Input. Supports *, **…

YAML Tools

  • YAML Formatter

    Pretty-print YAML with consistent indentation. Comments, anchors, and custom formatting are not pres…

  • YAML Syntax Checker

    Check whether YAML is syntactically valid. Supports multi-document files (--- separators). Schema va…

Markdown Tools

  • Markdown Preview

    Write Markdown and see HTML update live. Raw HTML is escaped for safety. Task lists stay plain text.…

  • Markdown to HTML

    Convert Markdown to HTML. Raw HTML is escaped for safety. Task lists stay plain list items — review …

Diff Tools

  • Text Diff

    Paste original and modified text to see a line-by-line unified diff. One panel may be left empty to …

  • JSON Diff

    Paste original and modified JSON to see structural changes (top-level keys, root arrays) and a forma…

Text Tools

  • Find & Replace

    Search for text and replace every match with new content. Use literal matching for exact strings or …

  • Remove Duplicate Lines

    Remove repeated lines from logs, CSV exports, or pasted lists. The first occurrence of each line is …

  • Sort Lines

    Sort lines alphabetically or flip line order from bottom to top. Choose Sort or Reverse in tool sett…

  • Remove Blank Lines

    Delete lines that are empty or contain only whitespace. Clean up copied text, configs, and log outpu…

  • Whitespace Tools

    Clean up pasted text by trimming line edges or collapsing irregular spacing. Choose Trim or Normaliz…

  • Line Ending Converter

    Detect and convert line endings in pasted text. Choose LF (Unix), CRLF (Windows), or CR (legacy Mac)…

  • Line Number Generator

    Prefix each line with a sequential number. Configure the starting number, separator, and optional ze…

  • Word Counter

    Get word, code point, line, and paragraph counts from any text. Paste content and click Run for a fu…

  • Character Counter

    Count Unicode code points, UTF-16 code units, line count, and UTF-8 byte size. Useful for limits on …

  • Slug Generator

    Convert titles and phrases into URL-safe slugs. Accented Latin letters are transliterated; other non…

  • Case Converter

    Transform text into another naming or display case. Choose the target format in tool settings. Struc…

  • Random String Generator

    Generate random strings using crypto.getRandomValues() with unbiased character selection. Set length…

  • Lorem Ipsum Generator

    Generate placeholder text for mockups and layouts. Choose paragraphs, sentences, or words in tool se…

Config Tools

  • chmod Calculator

    Convert between octal (755) and symbolic (rwxr-xr-x) permission modes. Four-digit octal shows setuid…

  • Connection String Parser

    Paste a connection URI to inspect protocol, host, port, database path, and query parameters. Passwor…

  • gitignore Generator

    Select templates in tool settings and optionally paste custom patterns in Input. Output is a startin…

Color Tools

  • Color Converter

    Convert a color from hex, rgb(), hsl(), or a common CSS color name to every common format. Space-sep…

  • Contrast Checker

    Enter foreground color in Input and background color in Tool Settings. Reports pass/fail for normal …