Developer
JSON, regex, CSV and developer tools
Select a tool below. Every tool runs locally in your browser and is free to use.
💻 Developer · Total 66 tools
Bảng mã ASCIIASCII table tool: lookup char decimal, hex and binary with search and copy for development and learning, with one-click copy, offline.
Base32 ConverterBase32 converter tool: support Base32 encoding and decoding with padding and bulk for development, with one-click copy, offline.
Base64 Image ViewerBase64 image viewer: paste Base64 to preview image with size and format conversion for development, with one-click copy, offline.
Brazil CPF ValidatorBrazil CPF validator: enter 11-digit CPF to validate for Brazil, multilingual.
Brazil PIX Key ValidatorBrazil PIX validator: enter CPF/CNPJ/email/phone/random key to validate PIX format for Brazil.
Conic Gradient GeneratorConic gradient generator: adjust angle, stops and center with live preview and CSS copy, animated for front-end gradien Supports batch processing and one-click copy.
Credit Card ValidatorCredit card validator: validate numbers with Luhn and detect Visa and Mastercard for payments and fraud prevention, with one-click copy and offline.
Cron Expression GeneratorCron generator: visually pick minute/hour/day/month/week to build Cron, parse and preview next runs for scheduling and DevOps.
Crypto Address ValidatorCrypto address validator: validate BTC/ETH and multi-chain formats with checksum, chain hints and error tips before transfers.
CSS Easing GeneratorCSS easing generator: visually adjust cubic-bezier curve to generate transition code with live preview for frontend and animation, with one-click copy and offline.
CSS Specificity CalculatorCSS specificity calculator: enter any selector to get specificity a,b,c with priority and override explanation for frontend debugging, one-click copy and offline.
CSS Units ConverterCSS units converter: convert px, rem, em, vw/vh and % by base font with responsive preview for front-end layouts. Supports batch processing and one-click copy.
CSV sang JSONCSV to JSON converter: convert tabular data to JSON array with delimiters and header detection for data, with one-click copy and offline.
CSV ViewerCSV viewer: paste CSV data to parse as table supporting comma, semicolon and Tab with quoted fields for data viewing and cleaning, with one-click copy and offline.
HTTP to cURL ConvertercURL converter: generate cURL commands from method, URL, headers and body with import for API debugging, with one-click copy and offline.
cURL to HTTP RequestcURL to HTTP parser: paste cURL to get method, URL, headers and body with highlighting and copy for API debugging and d Supports batch processing and one-click copy.
Email Address ValidatorEmail validator: check length, username and domain labels with clear tips per RFC for registration, with one-click copy and offline.
EU VAT Number ValidatorEU VAT number validator: enter VAT number to validate format with country prefix.
Chuyển đổi qua lại giữa tên cột và số thứ tự ExcelExcel column name converter: convert between letters and numbers A1 AB28 XFD16384 bidirectionally with batch for spreadsheets, with one-click copy and offline.
Excel Formula GeneratorExcel formula generator: pick function type and fill parameters to generate copy-ready formulas with examples for spreadsheets, with one-click copy and offline.
File Hash CalculatorFile hash calculator: compute SHA-1 and SHA-256 checksums of files locally for privacy for verification and security, with one-click copy and offline.
File to Base64File to Base64: upload any file to generate Base64 and Data URL with image preview and copy for front-end embedding and API debugging.
Flexbox GeneratorFlexbox generator: adjust direction, alignment and gap with live preview and CSS copy for front-end flex layouts and responsive design.
Git CheatsheetGit cheatsheet: browse common commands by scenario like commit and branch with search and copy for developers, with one-click copy and offline.
Git Commit Message GeneratorGit commit message generator: generate Conventional Commits messages with type and scope for development and collaboration, with one-click copy and offline.
Hex Dump ToolHex dump viewer: upload file or paste text to get hex and ASCII view with offset, width and search for reverse engineering and debugging.
hreflang Tag GeneratorHreflang generator: generate alternate link tags for multilingual sites with validation for SEO, with one-click copy and offline.
HTML Entities Encode/DecodeHTML entities converter: encode special characters to HTML entities or decode back with preview for web, with one-click copy and offline.
Công cụ định dạng HTMLHTML formatter: paste HTML to beautify or minify with highlighting and error hints for front-end and code cleanup. Supports batch processing and one-click copy.
HTML Live PreviewHTML preview: paste HTML/CSS/JS for live rendered preview with split view and copy for front-end debugging and template Supports batch processing and one-click copy.
HTML to JSXHTML to JSX: transforms HTML snippets to React JSX handling class and style. For frontend. Supports batch processing, export and one-click copy, offline use.
HTML to Text ToolHTML to text: extract text from HTML preserving paragraphs with tag stripping and entity decoding for content cleaning. Supports batch processing and one-click copy.
HTTP Methods ReferenceHTTP methods reference: explains GET, POST, PUT, PATCH, DELETE usage and idempotency. Supports batch processing, export and one-click copy, offline use.
IBAN ValidatorIBAN validator: validate country code length and mod-97 checksum for international transfers, with one-click copy and offline.
India PAN ValidatorIndia PAN validator: enter 10-character PAN to validate format for India.
Japan Invoice Number ValidatorJapan invoice number validator: enter 13-14 digit registration number to validate for Japan.
Japan My Number ValidatorJapan My Number validator: enter 12-digit number to validate checksum for Japan.
JSON Diff ToolJSON diff tool: paste two JSON documents to find added, removed and changed paths with highlighting for API and config comparison, with one-click copy and offline.
Định dạng/Nén/Xác thực JSONJSON formatter: paste JSON to beautify, minify and validate with highlighting and error location for dev debugging. Supports batch processing and one-click copy.
JSON Formatter & ValidatorJSON formatter: beautify, validate and minify to single line with custom indent and character count for development and debugging, with one-click copy and offline.
JSON MergeJSON merge: merge multiple JSON objects with deep merge and conflict strategies for config and data integration. Supports batch processing and one-click copy.
JSON Minifier & BeautifierJSON minifier and beautifier: compress or beautify JSON showing byte count and savings in real time for API debugging, with one-click copy and offline.
JSON Path QueryJSON path query tool: enter JSON and dot-path with array indexes to extract values quickly with highlighting for API debugging, one-click copy and offline.
JSON Schema GeneratorJSON Schema generator: pastes sample JSON to auto generate JSON Schema with nested fields. Supports batch processing, export and one-click copy, offline use.
JSON to Markdown TableJSON to Markdown converter: convert object array to Markdown table with header and alignment for docs and README, with one-click copy and offline.
JSON to XMLJSON to XML converter: paste JSON to get well-formed XML with attribute and array handling, formatting and validation for integration.
CSS Loader GeneratorLoader generator: customize spinner, skeleton and progress loaders with CSS copy for front-end loading states. Supports batch processing and one-click copy.
Trình chỉnh sửa Markdown trực tuyếnMarkdown editor: edit on left and preview on right supporting headings, lists and code blocks for writing and docs, with one-click copy and offline.
SEO Meta Tags GeneratorMeta tags generator: enter title, description and keywords to generate SEO Meta and Open Graph tags for web optimizatio Supports batch processing and one-click copy.
Mexico CURP ValidatorMexico CURP validator: enter 18-character CURP to validate format for Mexico.
Mexico RFC ValidatorMexico RFC validator: enter RFC to validate format for Mexico SAT.
Neumorphism GeneratorNeumorphism generator: adjust shadow, radius and background with live preview and CSS copy for card and button design. Supports batch processing and one-click copy.
Password Entropy CalculatorPassword entropy calculator: analyze charset, length and entropy with crack time estimate for security, with one-click copy and offline.
Random Password GeneratorRandom password generator: customize length and character types showing entropy for accounts, with one-click copy and offline.
Công cụ chuyển đổi PX và REM/EMPX to REM converter: convert px, rem and em based on root font size 16px for responsive and mobile styles, with one-click copy and offline.
README GeneratorREADME generator: enter project name, description, install and usage to generate standard Markdown README for open source and docs, with one-click copy and offline.
Regex EscapeRegex escape tool: auto escape strings for regex with bulk and preview for development and text processing, with one-click copy, offline and multilingual.
Công cụ kiểm tra Biểu thức Chính quyRegex tester: test regex against text with live highlighting and match count for development, with one-click copy and offline.
robots.txt GeneratorRobots.txt generator: create crawler rules with allow disallow, sitemap and validation for SEO and site management, with one-click copy, offline and multilingual.
SemVer CompareSemVer compare tool: compare two versions and parse major minor patch and prerelease for dev and release management, with one-click copy, offline.
Sitemap GeneratorSitemap generator: create XML sitemap from URL list with priority and frequency for SEO and site management, with one-click copy, offline and multilingual.
JSON-LD Structured Data GeneratorStructured data generator: create JSON-LD by type with validation and preview for SEO and site management, with one-click copy, offline and multilingual.
Công cụ so sánh khác biệt văn bảnText diff tool: highlight differences between two texts with line and character diff for proofing and version compare, with one-click copy, offline.
CSS Transform GeneratorTransform generator: visually generate CSS transform code with translate, rotate and scale preview for frontend and design, with one-click copy, offline.
User-Agent GeneratorUser agent generator: create random UA for browsers and devices with custom and bulk for testing and crawling, with one-click copy, offline.
Định dạng XMLXML formatter: beautify with indentation supporting comments and CDATA with validation for config, with one-click copy and offline.
FAQ
What is the Developer category?
The Developer category includes 66 free online tools for common needs. All run locally in your browser - no sign-up or install required.
Are these tools free?
Yes, all tools are free with no usage limits.
Do I need to register?
No. Open a page and use it right away - your data stays in your browser.
Which languages are supported?
This site supports 12 languages: Chinese, English, Japanese, Korean, Spanish, French, German, Portuguese, Russian, Arabic, Indonesian and Hindi.