developer

Find and Replace — Replace any pattern in your text — exact match or regex, case-sensitive or not. Runs entirely client-side inside your browser.

Compare Two Lists — Drop two newline-separated lists into the boxes and instantly see what is shared, what is unique to each, and the merged union.

HTML Entity Encoder / Decoder — Convert text to safe HTML entities, or decode entities back to characters. Minimal, named, or numeric output.

Morse Code Translator — Translate text to and from International Morse Code — dots, dashes, slashes between words.

Free online HTML entity converter. Encode text to named, decimal, or hex HTML entities and decode entities back to text.

Encrypt and decrypt messages with PGP right in your browser. Generate RSA 4096 key pairs. 100% client-side — keys never leave your device.

Strip HTML Tags — Paste HTML and get back the plain text content — tags removed, entities decoded, scripts and styles stripped.

Filter Lines by Substring — Drop every line that contains a pattern — or keep only the lines that do. Plain substring matching or full regex.

Remove Accents — Strip every accent and diacritical mark from your text. Café becomes cafe, niño becomes nino, résumé becomes resume.

Add Prefix / Suffix to Lines — Add the same prefix or suffix (or both) to every line of your text. Runs entirely client-side inside your browser.

HTML Editor (WYSIWYG) — A simple in-browser WYSIWYG editor — format with the toolbar, paste rich text from Word or web pages, and copy the resulting HTML.

JSON Formatter / Validator — Format, minify, or validate any JSON in your browser. Choose indent style and see error details for invalid input.

Markdown to HTML — Convert Markdown to HTML with live side-by-side preview. Supports headings, lists, links, images, code blocks, blockquotes, and empha...

Text Diff / Compare — Compare two blocks of text and see exactly what changed — added lines in green, deleted in red, unchanged in gray.

JWT Decoder — Paste a JWT and see the header, payload, expiry, and signature parts decoded. Everything happens in your browser.

CSV ↔ JSON — Convert tabular data between CSV and JSON. Header row detection, custom delimiter, quoted-field-with-comma support.

Regex Tester — Test JavaScript regular expressions live — see matches highlighted in your text and captured groups in a list.

Color Converter — Convert between HEX, RGB, HSL, and RGBA — pick a color or type any format and the others update live.

Number Base Converter — Convert numbers between decimal, hex, binary, octal — or any arbitrary base from 2 to 36.

JSON Diff — Compare two JSON values structurally — see exactly what was added, removed, or changed, with full key paths.

Cron Expression Builder — Edit a 5-field cron expression and see plain-English description plus the next 5 fire times in your local timezone.

Meta Tag Generator — Generate SEO meta tags, Open Graph tags, and Twitter Card tags for any page — with a live Google search-result preview and length w...

Color Palette Generator — Pick a base color and generate a harmony palette — complementary, analogous, triadic, tetradic, split-complementary, monochrom...

CSS Gradient Generator — Build linear, radial, or conic CSS gradients visually. Add unlimited color stops, drag the angle, see the live preview, and cop...

Box Shadow Generator — Build CSS box-shadow visually — tune offset, blur, spread, color, opacity, and inset with live preview.

Markdown Table Generator — Build Markdown tables with a visual cell editor — set rows/columns, click to edit any cell, pick alignment, or import from CSV.

Color Contrast Checker — Pick a foreground and background color and instantly see the WCAG 2.1 contrast ratio with pass/fail badges for AA and AAA, norm...

SQL Formatter — Paste any SQL query and get it formatted with proper indentation, keyword casing, and clause breaks. Supports 10 dialects including Post...

YAML Formatter — Paste any YAML and format it cleanly — pick indent width and line wrap, optionally sort keys. Also validates YAML syntax and converts b...

JSON to TypeScript — Paste a JSON payload and instantly get TypeScript interfaces (or type aliases) describing its shape. Optionally mark all properties...

Cron Visualizer — Paste any 5-field cron expression and instantly see: a plain-English description, a field-by-field breakdown, and the next 10 schedule...

GitHub Badge Maker — Generate Shields.io-style SVG badges for any GitHub README. Pick label, value, colors and one of four styles (flat, flat-square, fo...

JWT Encoder / Signer — Build and sign a JWT — pick HS256 / HS384 / HS512, paste a header and payload (JSON), provide your secret, get a signed token. Us...

MIME Type Lookup — Type a file extension (or filename) and get the proper Content-Type header value. Reverse lookup too — type a MIME type ...

JSON to Go Struct — Paste a JSON sample and get matching Go struct definitions — with optional json:"..." tags, omitempty, and...

JSON to JSON Schema — Paste any JSON sample and get a JSON Schema describing its shape — useful for API documentation, request/response validation, and ...

JSON to Zod Schema — Paste JSON and get a ready-to-use z.object({...}) Zod schema plus the inferred TypeScript type.

HTML to Markdown Converter — Paste any HTML snippet — from a blog post, a CMS export, or a webpage — and get clean Markdown ready for static site genera...

Pick any color and get its HEX, RGB, HSL, and HSV values instantly. Free online color picker with eyedropper and color harmony.

.htaccess Generator — Generate .htaccess rules for common Apache web server configurations — redirects, caching, password protection, hotlink blocking, ...

Minify CSS code online. Remove comments, whitespace, and unnecessary characters to reduce file size. Free CSS minifier — instant results.

Minify HTML code online. Remove comments, collapse whitespace, and reduce file size. Free HTML minifier — instant results in your browser.

Parse any URL into its components: protocol, hostname, port, path, query parameters, and hash. Free online URL parser tool.

Parse user agent strings to identify browser, operating system, and device type. Free online user agent parser with instant results.

QR Code Reader — Upload a QR code image to decode its contents. Supports drag-and-drop, file upload, and clipboard paste. Extracts URLs, text, and other...

MIME Type Checker — Enter a file extension or MIME type to look up the corresponding type. Supports 160+ common file formats including web, office, medi...

JavaScript Minifier — Paste your JavaScript code to minify it instantly. Removes comments, collapses whitespace, strips console.log and debugger stateme...

RGB to HEX Converter — Convert between RGB, HEX, HSL, and RGBA color formats with a live color preview. Enter a value in any format and see all conversi...

Generate HTML table markup from delimited text data. Supports tab, comma, CSV, and custom delimiters. Free online HTML table generator.

Barcode Reader — Upload an image containing a barcode or QR code to instantly decode its content. Supports multiple barcode formats.

Free online file MIME type checker. Upload any file to detect its MIME type, file extension, description, and size.

免费的在线文本差异对比工具。支持双栏左右对照，精准高亮显示行级别差异以及字符级别的添加和删除。

JSON Schema Builder — Build JSON validation models visually. Configure properties, toggle required attributes, and instantly copy JSON Schema, Zod code,...

Regex Explainer — Deconstruct regular expressions. Analyze quantifiers, capture groups, sets, boundaries, and flags with clear explanations.

Free online code minifier. Compress HTML, CSS, and JavaScript code instantly in one place. Removes comments, whitespace, and formatting to optimize speed.

Generate JSON-LD structured data for Article, Product, LocalBusiness, FAQPage, Organization, BreadcrumbList, and Event schema types instantly.

Paste your URLs and generate a valid XML sitemap with changefreq, priority, and lastmod. Download sitemap.xml instantly — no signup needed.

Visually craft CSS border-radius — independent corners, px/%/em units, and organic blob shapes. Live preview and copy-paste CSS. Runs in your browser.

Design frosted-glass CSS with live preview — blur, saturation, fill opacity, border and shadow. Copy backdrop-filter CSS. Runs in your browser.

Create CSS clip-path shapes visually — polygons, circles, insets and 20+ presets with draggable points. Live preview and copy-paste CSS, in your browser.

Design CSS cubic-bezier easing curves with a draggable editor, presets, and a live animation preview. Copy the timing-function CSS, all in your browser.

Design CSS text-shadow visually — stack multiple layers, pick neon, 3D, outline and retro presets, then copy the CSS. Live preview, runs in your browser.

Build soft-UI neumorphism CSS visually — base color, light direction, shape and shadow distance. Copy box-shadow CSS. Live preview in your browser.

Make CSS triangles with the border trick — choose direction, width, height and color, preview live, and copy the width/height/border CSS. Runs in browser.

Visually build a CSS filter — blur, brightness, contrast, grayscale, hue, sepia and drop-shadow — preview on your own image and copy the CSS. In-browser.

Build CSS transforms visually — translate, scale, rotate, skew plus 3D rotateX/Y/Z and perspective. Live preview on a grid and copy the CSS, in-browser.

Build CSS @keyframes animations — fade, slide, bounce, pulse, spin, flip, zoom — tune duration, easing, delay and loop, preview live and copy the CSS.

A visual CSS flexbox playground — tweak direction, justify, align, wrap and gap, watch the live preview, and copy the container CSS. Runs in your browser.

A visual CSS grid playground — set columns, rows, gaps and track sizing, watch the live preview, and copy the generated grid CSS. Runs in your browser.

Design a CSS button visually — padding, colors, gradients, border-radius, shadow and hover effects — with a live preview, then copy the CSS. In-browser.

Style custom scrollbars visually — width, track and thumb colours, hover and radius — with a live WebKit preview and Firefox fallback. Copy the CSS.

Calculate file or text hashes online — MD5, SHA-1, SHA-256, SHA-512. Verify file integrity by comparing a known checksum. Free, in your browser.

Inspect a PDF's internal structure as formatted JSON. See objects, streams, cross-reference tables, and page trees. Developer tool, in-browser.

Write HTML, CSS, JS in tabbed editors with live iframe preview. Auto-run, download as HTML file. Preloaded counter app sample. No server — pure browser.

Calculate and compare CSS selector specificity instantly. See (a,b,c) breakdown, visualize with bar charts, and find which selector wins. Free developer tool.

Paste SVG path data and see it rendered live. View control points for bezier curves. Supports all path commands (M, C, S, Q, T, A, Z). Free developer tool.

Interactive searchable reference for all HTTP status codes (1xx-5xx). Click to copy, filter by category. Free developer tool, no signup.

Free online Markdown editor with live preview, toolbar, GFM tables, RTL direction support for Arabic, Persian, Urdu, Hebrew. Download as HTML or Markdown. No signup.

Free online css unit converter. No signup, no upload — works entirely in your browser. Fast, private, and free forever.

Free online api tester. No signup, no upload — works entirely in your browser. Fast, private, and free forever.

Free online json toolkit. No signup required.

UUID Generator — Generate UUIDs in bulk — v4 (random) or v7 (time-ordered). Optional uppercase and braces. Runs entirely client-side inside your browser.

Random String Generator — Produce one or many cryptographically random strings — pick the length, the character classes, and how many you need.

Combination Generator — Generate every unordered combination of K items chosen from your list — every way to pick a subset of the size you specify.

Robots.txt Generator — Build a robots.txt — allow / disallow rules per user-agent, optional crawl-delay, and sitemap URL.

Email Signature Generator — Build an email signature with your name, title, contact info, social handles, and optional logo. Three style presets: modern...

WhatsApp Link Generator — Build a wa.me click-to-chat link — enter an international phone number and an optional pre-filled message. Get th...

SEO Tags Generator — Enter your page details to generate complete SEO meta tags including Open Graph and Twitter Card tags for social media sharing.

Mailto Link Generator — Generate mailto: links with pre-filled recipients, subject, and body. Get both the raw URL and ready-to-use HTML anchor code.

Disemvowel — Drop every vowel from your text. Useful for compression sketches, puzzles, censoring, and quick obfuscation.

Free online BBCode to HTML converter. Convert BBCode tags like [b], [i], [url], [img], [quote], [list], [color], and more to clean HTML markup.

Text to Speech — Type or paste text and have it read aloud using your browser's built-in speech synthesis. Choose from available voices and adjust rate ...

CSV Stats — Per-column statistics for any CSV — total count, non-empty, unique values, plus numeric min/max/mean/sum for any column with numbers.

Convert a CSV to SQL INSERT statements for MySQL, PostgreSQL, SQLite or MS SQL. Optional CREATE TABLE, multi-value INSERT mode.

JSON to CSV — Convert any JSON array (of objects or arrays) — or even a single object — into clean CSV. Tick the Flatten option to expand nested objects...

Convert TSV (tab-separated values) to JSON online. Use the first row as keys, auto-parse numbers and booleans, and copy the formatted output instantly.

DOCX to HTML — Convert a .docx Word document to clean, semantic HTML — headings, bold/italic, lists, links, and tables are all preserved.

XLSX to JSON — Convert any Excel sheet to JSON — array of objects keyed by header row, or array of arrays with no header.

Convert HTML to PDF — open in a print preview for high-fidelity output, or download a smaller text-only PDF. Browser-based, no upload.

EPUB to HTML — Drop an .epub and get all chapters merged into one clean HTML document — wrap as standalone, optionally strip inline styles and class nam...

App Icon Generator — Upload one 1024×1024 (or larger) image and instantly get every icon size required by iOS, Android, Google Play and the App Store — ...

Mobile Wallpaper Generator — Drop one image and get it auto-resized to every common phone, tablet, and desktop wallpaper resolution — iPhone 15 Pro Max,...

Open Graph Image Generator — Generate 1200×630 Open Graph cards, Twitter / LinkedIn social images, square Instagram-style images, or 9:16 story cards. D...

YouTube Thumbnail Maker — Build YouTube thumbnails — 1280×720 with a bold title overlay, optional background image, theme presets (bold yellow, red arro...

Instagram Carousel Slicer — Slice one wide image into 2 to 10 Instagram carousel slides — square, 4:5 portrait (recommended), or 9:16 story. Pick slice ...

Discord / Slack Emoji Optimizer — Resize and auto-compress images to fit emoji upload limits — Discord (≤256 KB), Discord Nitro animated (≤512 KB), Slac...

免费在线 App Store 和应用商店截图制作工具。将您的移动应用界面装入 iPhone 或 Pixel 手机边框中，搭配渐变背景和精美文案标题。

Free online SSL certificate checker. Verify SSL/TLS certificate details for any domain including issuer, expiry date, validity, and serial number.

Free online drywall calculator. Calculate drywall sheets, screws, joint compound, and tape needed for any room. Supports 4x8, 4x10, and 4x12 sheets.

Training Volume Calculator — Log your exercises and sets to calculate your weekly workout volume load per muscle group and compare it against muscle-bui...

Audio BPM Detector — Calculate the Beats Per Minute (BPM) of any song or audio track instantly. Simple, fast, and runs entirely in your browser using We...

Text Stats — Deep-dive into your writing metrics. Calculate readability scores, average word/sentence lengths, reading and speaking times, and clean cha...

Free online Ohm's Law calculator. Calculate voltage (volts), current (amps), resistance (ohms), and power (watts) with any two known values.

AC Power Calculator — Calculate single and three-phase AC electrical power parameters, including Watts, Volt-Amperes, and Amps.

Sign a PDF in your browser — draw, type, upload an image, or stamp, then drag and resize the box to place it exactly. No uploads, fully private.

Add APPROVED, DRAFT, CONFIDENTIAL, PAID or custom stamps to a PDF and place them precisely with a draggable box. Runs entirely in your browser.