All tools

54 tools · 10 categories

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

  1. Text Counter

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

  2. 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.

  3. Text Replace

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

  4. Text Cleaner

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

  5. Line Tools

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

  6. Regex Tester

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

  7. JSON Formatter

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

  8. 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.

  9. JSON Converter

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

  10. 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.

  11. SQL Formatter

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

  12. CSV Tools

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

  13. 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.

  14. 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.

  15. 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.

  16. Base64 Encoder and Decoder

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

  17. 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.

  18. HTML Encoder and Decoder

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

  19. 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.

  20. 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.

  21. 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.

  22. 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.

  23. 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.

  24. 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.

  25. Password Generator

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

  26. 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.

  27. HMAC Generator

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

  28. 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.

  29. User-Agent Parser

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

  30. URL Tools

    Parse URL structure, convert query strings to JSON, normalize canonical variants, strip tracking parameters, and run a quick safety review for.

  31. 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.

  32. Subnet Calculator

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

  33. Browser Compatibility Detector

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

  34. Image Compressor

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

  35. 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.

  36. 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.

  37. 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.

  38. 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.

  39. EXIF Remover

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

  40. Color Converter

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

  41. Gradient Generator

    Create visually appealing CSS gradients with custom colors, directions, and opacity for UI elements, backgrounds, and branding designs.

  42. Contrast Checker

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

  43. Palette Generator

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

  44. Timestamp Converter

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

  45. Timezone Converter

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

  46. Date Calculator

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

  47. World Clock

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

  48. 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.

  49. 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.

  50. 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.

  51. 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.

  52. 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.

  53. 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.

  54. 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.

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.