⚑ deftools.io

Free developer tools that run entirely in your browser. No accounts, no tracking, no server roundtrips.

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πŸ”§ Developer Tools 38

πŸ” Base64 Encode/Decode
Encode text to Base64 or decode Base64 back to text. Unicode-safe, URL-safe mode, file support.
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ASCII Art Generator
Convert text to ASCII art. Choose from multiple fonts and styles. Copy the output with one click.
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chmod Calculator
Compute Unix file permissions: toggle read/write/execute for user, group, others. Get numeric, symbolic, and full chmod commands.
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Cipher Playground
Encode & decode classic ciphers: Caesar, ROT13, Atbash, Vigenère, A1Z26, Morse, Binary, Hex, Rail Fence, Bacon. Live preview, deep-link, copy, history.
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Commit Message Builder
Build clean Conventional Commits messages with live preview, scope, breaking-change flags, footers, and gitmoji. Copy-ready output, deep-link share, and recent history.
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Cron Expression Explainer
Parse any cron expression into a human-readable schedule and preview upcoming run times.
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CSS Minifier
Minify and beautify CSS instantly. Strip comments, whitespace, and redundant semicolons β€” or pretty-print minified CSS back to readable format. 100% client-side.
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CSS Specificity Calculator
Calculate and compare CSS selector specificity. Visualizes ID, class, and element scores. Supports multiple selectors for comparison.
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Curl β†’ Code
Convert curl commands to Python, JavaScript, and Go code.
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Diff Checker
Compare two pieces of text line by line with word-level highlighting. Shows additions, deletions, and similarity.
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Hash Generator
Generate MD5, SHA-1, SHA-256, SHA-384, SHA-512 hashes from text or files. Hex, Base64, or Base64URL output. Verify a hash against input. 100% client-side via Web Crypto + pure-JS MD5.
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HTML Entity Encoder
Encode and decode HTML entities. Convert special characters.
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HTML Playground
Live HTML/CSS/JS sandbox. Write code in three panes, see instant preview in a sandboxed iframe, capture console output, share via deep-link. 100% in-browser, nothing sent anywhere.
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HTTP Method Reference
Quick reference for all HTTP methods. Learn what each method does, when to use it, and see code examples.
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HTTP Status Codes
Searchable reference for all HTTP status codes (1xx–5xx). Filter by category, copy responses, see usage examples.
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JSON β†’ TypeScript
Generate TypeScript interfaces from JSON. Paste JSON, get typed interfaces.
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JSON Diff
Compare two JSON objects semantically. Shows added, removed, changed, and type-changed keys with full dot-path notation. Handles nested objects and arrays.
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JSON Formatter
Format, validate, minify and escape JSON. Real-time as you type.
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JSONPath Explorer
Query JSON with JSONPath expressions ($.store.book[*].author, $.users[?(@.age>18)]). Inline engine, no libraries. Live results, path highlighting, sample data, deep-linking. 100% client-side.
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JWT Debugger
Decode and inspect JSON Web Tokens. View header and payload.
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Key Code Inspector
Press any key to inspect its event properties β€” key, code, keyCode, location, modifiers, and friendly hotkey combo. Live modifier indicators, press history, copy-ready listener snippet, and a reference table of common key codes. Essential for building keyboard shortcuts, games, and accessible UIs. 100% client-side.
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Markdown Preview
Live Markdown preview with GitHub-style rendering. Type on the left, see the result on the right.
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MIME Type Lookup
Searchable database of MIME types and file extensions. Reverse lookup (extension β†’ MIME), forward lookup (MIME β†’ extensions), category filters, common-type cheatsheet, and copy helpers. 100% client-side.
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Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal. Real-time conversion.
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Number Stats
Paste a list of numbers and get instant descriptive statistics: count, sum, mean, median, mode, range, variance, standard deviation, quartiles, IQR, outliers, skewness, kurtosis, and a live histogram β€” 100% in your browser.
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Playwright Snippet Generator
Generate Playwright code snippets for common browser automation tasks. Supports selectors, actions, assertions, and more.
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Regex Tester
Test regular expressions with live highlighting, capture groups, replace mode, and common pattern presets.
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Screen & Device Info
Live viewport size, screen resolution, device pixel ratio, color scheme, orientation, network type, CPU cores, touch support, and more β€” everything a frontend developer needs for responsive testing. Updates in real time as you resize the window.
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Slug Generator
Convert titles to clean URL slugs. Unicode-aware, multi-line batch mode, custom separators.
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SQL Formatter
Format and beautify SQL queries. Supports keywords, joins, subqueries.
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Timestamp Converter
Convert Unix timestamps (seconds or milliseconds) to human-readable dates and back. Live conversion, multiple formats, relative time, and deep-link sharing.
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Unicode Inspector
Inspect every character's codepoint, UTF-8/UTF-16 bytes, HTML/JS/CSS/URL escapes, and block. Detects invisible, combining, control, and zero-width characters. 100% client-side.
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URL Encoder / Decoder
Encode and decode URLs, URI components, and query strings. Supports encodeURIComponent, encodeURI, and base64.
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URL Parser
Parse any URL into its components: protocol, host, path, query params, hash. Edit fields and rebuild a URL, or share a parsed URL via deep-link.
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UUID / NanoID / ULID Generator
Generate UUID v4, UUID v7, NanoID, ULID and Short IDs. Bulk generate, format options, and inspect any ID to extract its timestamp. 100% client-side.
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WebSocket Tester
Test WebSocket connections, send messages, and view real-time responses. Supports multiple echo servers and custom endpoints.
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XML Formatter
Format, validate, minify and convert XML. Syntax-highlight, XML→JSON, stats, and tree view — all in your browser.
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YAML ↔ JSON
Convert between YAML and JSON formats. Real-time conversion.
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🌐 Domain & Network 6

πŸ” Security 5

✏️ Text & Data 7

🎨 Design 12

Box Shadow Generator
Create beautiful CSS box shadows with a visual editor. Copy the CSS in one click.
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Color Contrast Checker
Check WCAG color contrast ratios for accessibility compliance (AA, AAA).
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Color Converter
Convert colors between HEX, RGB, HSL, and named CSS colors. Pick any color and copy values instantly.
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Color Palette
Extract dominant colors from any image. Get hex, RGB, HSL values, contrast grades, copy-all-as-CSS, deep-link settings. 100% client-side median-cut quantization.
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CSS Filter Generator
Design CSS filter() effects visually. Adjust blur, brightness, contrast, hue-rotate, saturate, sepia, grayscale, invert and opacity with a live preview, then copy the CSS in one click.
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CSS Flexbox Generator
Visually design flexbox layouts. Adjust direction, alignment, wrap, gap, and item count β€” copy the CSS in one click.
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CSS Gradient Generator
Create beautiful CSS gradients with a visual editor. Linear, radial, and conic. Copy CSS in one click.
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CSS Grid Generator
Visually build CSS Grid layouts. Set columns, rows, gaps, and item placement β€” copy production-ready CSS in one click.
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CSS Transform Generator
Build complex CSS transforms visually β€” translate, rotate, scale, skew, and perspective on X/Y/Z axes. Live 3D cube preview, copy-ready CSS, and one-click presets.
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Cubic Bezier Generator
Design CSS easing curves visually. Drag control points on the bezier curve, preview live animations, and copy cubic-bezier() CSS in one click.
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Favicon Generator
Create favicons from emoji, letters, or text. Export PNG (16/32/48/64/180px) and ICO.
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SVG Path Visualizer
Paste any SVG path `d` attribute and inspect it live: anchor & control points, bounding box, path length, per-command breakdown. Auto-fit viewBox, grid, copy normalized path. 100% client-side.
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πŸ“± Media 4

⏱️ Productivity 3

πŸ“ Everyday Tools 2

πŸ“£ SEO / Social 3

πŸ”§ CSS & Design 3

πŸ”§ Network Tools 1

πŸ”§ Finance Tools 2

πŸ”§ Math Tools 3

πŸ”§ Music & Audio 1

πŸ”§ Fun 1

πŸ”§ Text Tools 1

πŸ”§ Time & Date 1