All tools

107 tools · 10 categories

Every developer utility DevKitLab ships, on one page. Real-time search, keyboard navigation, everything runs locally in your browser.

  1. JSON Formatter

    Format, minify, validate, and inspect JSON with error positioning for API responses, config files, and debugging logs.

  2. JSON Diff

    Compare two JSON documents with a git-style side-by-side or unified view, structural change list keyed by JSON Path, and word-level diff for long strings.

  3. JSONPath & jq Evaluator

    Test JSONPath expressions and run jq filters on one page to extract nested fields, filter arrays, aggregate JSON, and see match counts as you type.

  4. JSON Converter

    Convert JSON to YAML, XML, CSV, TOML, JavaScript object literals, and PHP arrays locally with format-specific conversion options.

  5. JSON to Types Generator

    Generate TypeScript, Go, Rust, Swift, Kotlin, Python, and more type definitions from a JSON sample, with inferred fields, entirely in the browser.

  6. YAML Converter

    Convert YAML to JSON, TOML, XML, JavaScript objects, or PHP arrays. Multi-document YAML merges into a JSON array, anchors and aliases expand by default, and common traps such as the Norway problem, version-as-float, and tab indentation surface as hints.

  7. SQL Formatter

    Beautify, indent, and normalize SQL across MySQL, PostgreSQL, SQLite, BigQuery, Snowflake, and many other dialects.

  8. XML Formatter

    Pretty print, indent, minify, and validate XML in the browser, with element folding, syntax highlighting, and line and column error reporting.

  9. XML Converter

    Convert XML to JSON, YAML, TOML, JavaScript objects, or PHP arrays. Elements map to keys, repeated siblings become arrays, and attributes map to prefixed fields with optional value typing.

  10. TOML Converter

    Convert TOML to JSON, YAML, XML, JavaScript objects, or PHP arrays. TOML tables become objects, arrays of tables become arrays, and date-times plus 64-bit integers stay clear.

  11. CSS Minifier

    Minify CSS with a real parser that strips comments and whitespace, shortens values, and can merge rules, with live gzip size.

  12. CSS Beautifier

    Reformat minified or one-line CSS into a readable stylesheet, with consistent indentation, one declaration per line, and your choice of indent and width.

  13. JavaScript Minifier

    Minify JavaScript with Terser to compress, mangle local names, and drop dead code, with live gzip size and a saved percentage.

  14. JavaScript Beautifier

    Reformat minified or bundled JavaScript into readable code, with proper indentation, line breaks, and your choice of semicolons and quote style.

  15. HTML Minifier

    Shrink HTML and the CSS and JavaScript embedded in it, collapsing whitespace and comments while keeping the page rendering identical.

  16. HTML Beautifier

    Reformat minified or one-line HTML into a readable, indented document, formatting the CSS and JavaScript embedded in it in the same pass.

  17. SVG Optimizer

    Optimize and minify SVG with the svgo engine, stripping editor metadata and rounding coordinates, with a live preview and gzip size.

  18. CSV Tools

    View, edit, parse, and export CSV in the browser with delimiter, quoting, escaping, table preview, and JSON conversion support.

  19. Number Base Converter

    Convert numbers between binary, octal, decimal, hexadecimal, and any base from 2 to 36 in the browser, with support for negatives, big integers, prefixes, and grouped output.

  20. Unit Converter

    Convert between common units across 20+ physics and engineering categories including length, mass, duration, temperature, area, volume, speed, pressure, energy, power, information, frequency, and electrical quantities.

  21. Map Coordinate Converter

    Convert a coordinate between WGS84, GCJ-02 (Amap/Tencent), BD-09 (Baidu), Web Mercator, CGCS2000, and global EPSG systems, with every target shown at once.

  22. Image Compressor

    Compress JPEG, PNG, and WebP images locally for hero images, product photos, article assets, and batch media delivery.

  23. Image Resizer

    Resize images and photos locally to exact pixel dimensions, by percentage, longest edge, or social presets, with aspect-ratio lock and crop or pad, and batch processing.

  24. Image Cropper

    Crop images locally in the browser with a draggable crop box, aspect-ratio lock, rotate, flip and fine straightening, and ten crop shapes from circle and rounded to hexagon, star and heart, exported as PNG, WebP, or JPEG.

  25. Image Converter

    Convert JPEG, PNG, and WebP into WebP, JPEG, PNG, AVIF, or lossless optimized PNG in the browser. Compare output size and keep originals safe.

  26. Image to Base64

    Encode images to Base64 text locally in the browser. Switch the same result between Data URL, raw Base64, CSS, HTML, and Markdown output.

  27. Base64 to Image

    Decode Base64, Data URL, CSS, HTML, or Markdown image payloads back to a real image in the browser. Auto-detects MIME and supports preview and download.

  28. Image Metadata Viewer

    Read EXIF, GPS, IPTC, XMP, and ICC metadata locally in the browser. Grouped readable view, raw JSON view, and JSON copy and download.

  29. EXIF Remover

    Strip EXIF, GPS, camera model, capture time, and XMP metadata from JPG, PNG, and WebP images locally in the browser before publishing.

  30. Batch Rename Files

    Rename many files at once with a bulk file renamer: replace text, add prefixes or suffixes, number files, fix extensions, preview changes, then rename in place or export a script.

  31. Archive Extractor

    Open ZIP, 7z, RAR, TAR, gzip, and other archives in the browser, browse what is inside, then download a single file or repackage everything as a ZIP. Password-protected archives are supported and nothing is uploaded.

  32. Favicon Generator

    Generate a full favicon set from one image: favicon.ico, PNG icons, Apple touch icon, Android Chrome icons, and a web app manifest, all in the browser.

  33. PDF Merge

    Combine multiple PDFs into one file in the browser. Reorder documents before export, choose a filename, and keep the merge workflow local.

  34. PDF Split

    Split one PDF by page ranges, every N pages, or single pages in the browser, then download the results together as a ZIP.

  35. PDF Watermark

    Add text or image watermarks to PDFs in your browser. Adjustable opacity, rotation, color, font size, 9-grid positioning, tiling, and Chinese / Japanese fonts.

  36. Organize PDF

    Organize PDF pages with thumbnails. Delete, reorder, rotate, and extract selected pages in the browser without uploading the file.

  37. PDF to Image

    Render every page of a PDF to PNG, JPG, or WebP using pdf.js. Adjustable DPI, export ranges, JPG quality, and PNG transparency — all in your browser.

  38. Compress PDF

    Shrink PDFs in your browser. Two modes: structure compression keeps text and bookmarks (5-20% savings), or rasterize pages to JPEG (50-90%). Presets plus DPI and quality sliders.

  39. Encrypt & Decrypt PDF

    Set an open password on a PDF, or remove an existing password when you already know it. Runs entirely in the browser without uploading the file.

  40. Base64 Encoder and Decoder

    Encode and decode UTF-8 text, JSON, JWT segments, Basic Auth values, and URL-safe Base64 locally in your browser.

  41. URL Encoder and Decoder

    Encode and decode URL percent-encoding for values, full URLs, query parameters, and form-style spaces during API debugging, callback checks, and log cleanup.

  42. HTML Encoder and Decoder

    Encode and decode HTML entities for template text, attribute values, rich text, email source, CMS content, and log fields.

  43. Text to Binary

    Convert text to binary and decode binary back to text, with octal, decimal, and hex output, choosable delimiters, and a per-character ASCII and UTF-8 breakdown.

  44. Unicode Converter

    Encode text to Unicode escapes and decode them back, with JavaScript \u, U+ code points, HTML entities, and legacy %u output plus a per-character breakdown.

  45. Morse Code Converter

    Convert text to and from International Morse in the browser. Auto direction detection, Web Audio playback, Farnsworth spacing, screen flash sync, WAV export, plus key-the-code and listen-and-type practice drills.

  46. Punycode / IDN Converter

    Encode internationalized domain names to ASCII Punycode (xn--) and decode them back to Unicode, with a per-label breakdown and resilient label-by-label decoding.

  47. QR Code Generator

    Generate URL, text, Wi-Fi, email, phone, SMS, and vCard QR codes with logo, transparent background, gradients, Hex colors, error correction, and multiple downloads.

  48. QR Code Decoder

    Decode QR codes from images, screenshots, clipboard, camera, or screen capture. Batch-process many files, decode multiple QRs in a single image, parse Wi-Fi, vCard, email, SMS, geo, and calendar payloads, and export .vcf, .ics, annotated PNG, or bulk JSON / CSV.

  49. Barcode Generator

    Generate 1D and 2D barcodes such as Code128, Code39, EAN, UPC, ITF-14, PDF417, and Data Matrix with validation hints, a live preview, and PNG, SVG, or JPG export.

  50. Barcode Decoder

    Decode Code 128, Code 39, EAN, UPC, ITF, Codabar, PDF417, Data Matrix, Aztec, and other barcode images with upload, paste, camera scanning, inversion and upscaling retries, plus JSON and CSV export.

  51. Text Counter

    Count characters, words, sentences, paragraphs, lines, UTF-8 bytes, and reading time for content limits, API fields, and multilingual copy checks.

  52. Case Converter

    Convert headings, identifiers, slugs, and config keys between UPPER, lower, Capitalized, inverse, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, dot.case, and path/case.

  53. Text Replace

    Find and replace text with plain matching, case-sensitive matching, global replacement, and regex replacement for copy, config snippets, and logs.

  54. Text Cleaner

    Clean extra blank lines, repeated blank lines, leading and trailing whitespace, and trailing spaces from pasted text, logs, and drafts.

  55. Text Compare

    Compare two plain-text blocks, highlight added, removed, and edited lines, and call out word-level changes inside the line.

  56. Line Tools

    Process multiline text with line deduplication, sorting, numbering, prefix/suffix insertion, filtering, joining, splitting, and per-line regex replacement.

  57. Regex Tester

    Test JavaScript regular expressions live with match highlighting, capture groups, replacement preview, split output, ReDoS detection, and multi-language code export.

  58. Markdown Editor

    A Typora-style WYSIWYG Markdown editor with inline formatting, KaTeX math, tables, task lists, and fourteen switchable themes, all running locally in the browser.

  59. Invisible Character Viewer

    Reveal invisible characters in any text — spaces, tabs, line breaks, zero-width characters, the BOM, and Unicode control codes — named, counted, and color-coded, with one-click removal of the suspicious ones.

  60. Timestamp Converter

    Convert Unix seconds, milliseconds, readable date-time text, ISO/UTC values, and timezone-aware time formats.

  61. Timezone Converter

    Convert one source time into multiple target timezones with UTC offsets, abbreviations, and date-boundary notes.

  62. Date Calculator

    Calculate date differences, add or subtract dates, measure exact duration, and count business days or weekends.

  63. World Clock

    View current local time, UTC offsets, timezone abbreviations, and date-boundary notes for global cities.

  64. Cron Expression Tool

    Parse, build, and explain cron expressions locally in the browser, preview upcoming runs in any timezone, and use templates, a visual builder, local history, and TXT, CSV, JSON exports.

  65. Salary Ticker

    Turn your hourly, daily, monthly, or yearly pay into a live per-second earnings counter with a clock-out countdown, away-time passive income, overtime mode, privacy modes, and an always-on-top desktop widget.

  66. JWT Inspector

    Decode a JSON Web Token in the browser to read its header, payload, and claims, then verify or re-sign it with HMAC, RSA, ECDSA, or EdDSA keys.

  67. Password Generator

    Generate random passwords, memorable passphrases, and PINs locally with length, character groups, custom symbol sets, similar-character filtering, and strength scoring.

  68. Hash Generator

    Generate text and file hash digests with SHA-256, SHA-512, SHA3, BLAKE3, MD5, CRC, and xxHash for integrity checks, release verification, and data fingerprints.

  69. HMAC Generator

    Create HMAC-SHA256, HMAC-SHA512, and other keyed message authentication codes for API authentication, webhook verification, tamper checks, and file signature comparison.

  70. RSA Key Generator

    Generate RSA public and private key pairs in the browser for encryption and digital signatures, with selectable key size, hash, RSA-OAEP / RSA-PSS / PKCS#1 usage, and PEM, PKCS#1, JWK, and OpenSSH output.

  71. Certificate Decoder

    Decode X.509 certificates, certificate chains, and CSRs in the browser to read subject, issuer, validity, SANs, key usage, key size, and SHA-256 fingerprints.

  72. File Encryption

    Encrypt and decrypt any file locally with a password using AES-256-GCM, PBKDF2 key derivation, built-in integrity verification, password strength feedback, and chunked progress for archival, transfer, and cloud upload protection.

  73. htpasswd Generator

    Generate Apache and nginx .htpasswd credentials with bcrypt, Apache MD5, SHA-512 and more, plus a verify mode — all computed locally in your browser.

  74. Chmod Calculator

    Compute Unix file permissions with a visual rwx matrix and read the octal, symbolic, and chmod command at once. Handles setuid, setgid, and the sticky bit, applies symbolic operations like u+x or go-w, resolves umask values, and flags risky settings.

  75. User-Agent Parser

    Parse a User-Agent string into browser, operating system, device, rendering engine, app context, and bot signals.

  76. URL Tools

    Parse URLs, turn query strings into JSON, normalize links, remove tracking parameters, and flag risky patterns before sharing or debugging.

  77. HTTP Message Parser

    Detects raw HTTP messages, cURL commands, and fetch snippets, unpacks the request line, status, headers, query, cookies, and body into a structured view, and re-emits the same call as thirty-plus client formats and target languages.

  78. cURL Converter

    Convert a cURL command into the equivalent request in fetch, axios, Python requests, Go, Rust, PHP, Java, and around thirty other clients and languages, preserving method, URL, headers, cookies, and body, all in your browser.

  79. Cookie Parser

    Parse Cookie and Set-Cookie headers and document.cookie strings into name, value, and attributes, decode URL-encoded, JSON, Base64, and JWT values, audit Secure, HttpOnly, SameSite, prefixes, and size, and export to many formats.

  80. Subnet Calculator

    Calculate IPv4 subnet masks, network addresses, broadcast addresses, usable host ranges, and address counts from an IP and CIDR prefix.

  81. IP Address Converter

    Detect IPv4, IPv6, IPv4-mapped IPv6, and integer IPs, convert between dotted decimal, integer, hex, binary, and compressed IPv6, and build reverse DNS names.

  82. Browser Compatibility Detector

    Test the current browser for real support across web APIs, CSS, JavaScript, media, storage, security context, and device capabilities.

  83. ID Generator

    Generate browser-local UUIDs, random strings, numeric IDs, timestamp IDs, and custom rule IDs with prefix, suffix, batch copy, and TXT, CSV, JSON downloads.

  84. UUID Generator

    Generate UUID v1, v3, v4, v5, v6, v7, NIL, and MAX in the browser, with namespace and name input, batch counts, formatting, and click-to-copy or text download.

  85. Random Number Generator

    Generate random integers, decimals, dice roll totals, and arithmetic sequences with range, count, precision, duplicate, sorting, copy, TXT, JSON, and CSV export controls.

  86. Random String Generator

    Generate random strings, word slugs, sentences, paragraphs, and template-based codes with character sets, casing, separators, copy, TXT, JSON, and CSV export controls.

  87. Lorem Ipsum Generator

    Generate Lorem Ipsum placeholder text by paragraphs, sentences, words, or list items, with the classic opening, plain text or HTML output, and copy, TXT, and HTML download.

  88. Fake Data Generator

    Build structured JSON fake data with nested fields, arrays, locale-aware Faker rules, enums, ranges, nullable values, copy, JSON download, and reusable config import/export.

  89. ASCII Art Generator

    Convert text or images into ASCII art in the browser, with any-language text rendered through a canvas, image brightness mapped to characters, adjustable width and ramps, invert, and copy or text download.

  90. Slug Generator

    Turn any title into a URL-friendly slug, romanizing Chinese pinyin, Japanese, Korean, and Cyrillic to ASCII or keeping Unicode, with separators, casing, length limits, and batch de-duplication.

  91. Meta Tags Generator

    Generate a full set of HTML meta tags with Open Graph and Twitter Card tags, live Google and social previews, a canonical URL, share image, theme color, and a copyable head snippet.

  92. .gitignore Generator

    Generate a .gitignore from 300+ official github/gitignore templates for languages, frameworks, editors, IDEs, and operating systems, with presets, de-duplication, and instant copy or download.

  93. Color Converter

    Convert colors between HEX, RGB, HSL, and other formats for design, frontend development, and consistent visual presentation.

  94. Gradient Generator

    Create CSS gradients visually, tuning type, angle, center point, color stops, and opacity for UI backgrounds, component states, and brand visuals.

  95. Box Shadow Generator

    Build multi-layer CSS box-shadow with visual controls for offset, blur, spread, color, and opacity, then copy production-ready code.

  96. Contrast Checker

    Check text, icons, buttons, and UI component contrast against WCAG AA and AAA accessibility requirements.

  97. Palette Generator

    Generate OKLCH color scales, color schemes, neutral palettes, readable text colors, CSS variables, and JSON from one base color.

  98. SVG Pattern Generator

    Build tileable SVG background patterns with dots, grids, stripes, triangles, and waves, then copy CSS or download a clean SVG.

  99. Flexbox and Grid Generator

    Build responsive flexbox and CSS grid layouts visually with a live preview, then copy production-ready CSS for navbars, cards, and galleries.

  100. Cubic Bezier Generator

    Design CSS cubic-bezier easing curves by dragging control points, preview the motion live, and copy the transition timing function.

  101. CSS Animation Generator

    Build CSS keyframe animations from a library of fade, slide, zoom, and attention effects, preview the motion live, then copy the @keyframes and animation shorthand.

  102. PX to REM Converter

    Convert px, rem, em, pt, and % against an adjustable root font-size, build a modular type scale, generate fluid clamp(), and batch-convert a CSS block.

  103. HTTP Status Code Reference

    Search HTTP status codes by number, phrase, category, source, and troubleshooting context for APIs, websites, proxies, CDNs, redirects, authentication errors, rate limits, and gateway failures.

  104. Port Reference

    Search common TCP and UDP ports by number, protocol, service name, risk level, and exposure guidance for network configuration, firewall review, debugging, and security auditing.

  105. ASCII Table

    A complete, searchable ASCII and Latin-1 reference with decimal, hex, octal, binary, glyph, HTML entity, escape sequence, and plain-language explanations for every control character.

  106. HTML Entity Reference

    A searchable grid of every HTML named character reference, deduplicated to one card per character, with the glyph, code point, and one-click copy of the name, character, or numeric reference.

  107. Emoji Cheat Sheet

    A searchable cheat sheet of 1,870 emoji with GitHub shortcodes, names, tags, and code points, plus one-click copy of the emoji, shortcode, Unicode, or HTML entity.

About these tools

DevKitLab is a collection of developer utilities that does not ask you to sign up, install anything, or trust a server with your data. Every tool runs end-to-end in your browser: the JSON you paste, the file you drop, and the secret you type all stay on your device. Nothing is sent to our backend, nothing is captured by third-party analytics, and nothing persists once you close the tab. This is not a marketing line — it is the obvious default once you stop and ask why a quick HTTP status lookup or a one-off JWT decode should require trusting somebody else first.

Each tool is built to the same standard: do one thing well, expose enough of the internals that you can trust the result, and stay out of the way the rest of the time. Parsers surface every field instead of a summary, converters spell out the trade-offs between variants instead of hiding them behind a single toggle, generators take controllable parameters and reproducible seeds, and reference pages come with practical field notes rather than just quotes from the spec. The payoff is a set of utilities that holds up under the kind of time pressure you actually feel during debugging or release prep — instead of bookmarking four different sites for small tasks, you can usually reach the right tool with one or two keystrokes from the search box above and get back to the work that actually matters.