Ferramentas para desenvolvedores
Formate, converta, decodifique e teste — JSON, regex, JWT e mais.
Last updated: July 2026
UUID Generator
Generate random v4 UUIDs (GUIDs) in bulk and copy them with one click. Free, instant and fully in-browser using the secure crypto API.
Base64 Encode / Decode
Encode text to Base64 or decode Base64 back to text instantly. Free, private, in-browser — supports full Unicode (UTF-8).
JSON Formatter & Validator
Format, beautify, minify and validate JSON instantly. Free, private, in-browser JSON formatter with clear error messages.
Gerador de QR Code
Crie QR Codes grátis para links, texto, Wi-Fi e PIX-copia-e-cola — com cores e logo. Baixe em PNG ou SVG. Sem cadastro, no navegador.
Gerador de senhas
Gere senhas fortes e aleatórias com o tamanho e os caracteres que você escolher — criptograficamente seguras, geradas no seu navegador.
Number Base Converter
Convert numbers between binary, octal, decimal and hexadecimal instantly. Free in-browser hex-to-decimal and base converter.
Color Converter (HEX / RGB / HSL)
Convert colors between HEX, RGB and HSL, with a live colour picker and preview. Free, instant in-browser color converter.
Unix Timestamp Converter
Convert Unix epoch timestamps to human-readable dates and back, in local time and UTC. Free, instant, in-browser.
Hash Generator (SHA-256)
Generate SHA-1, SHA-256, SHA-384 and SHA-512 hashes of any text using the secure Web Crypto API. Free, instant, in-browser.
JWT Decoder
Decode a JSON Web Token (JWT) to read its header and payload instantly. Free, private, in-browser — no token is uploaded.
URL Encode / Decode
Encode text for safe use in URLs or decode percent-encoded URLs back to text. Free, instant, in-browser URL encoder/decoder.
HTML Encode / Decode
Encode HTML special characters to entities or decode entities back to text. Free, instant, in-browser HTML entity encoder/decoder.
JSON to CSV
Convert a JSON array of objects into CSV you can open in Excel or Sheets. Free, instant, in-browser JSON to CSV converter.
CSV to JSON
Convert CSV data into a JSON array of objects using the header row as keys. Free, instant, in-browser CSV to JSON converter.
Text Diff Checker
Compare two blocks of text and see added and removed lines highlighted. Free, instant, in-browser diff checker.
Text to Binary Converter
Convert text to binary and binary back to text (UTF-8). Free, instant, in-browser text-to-binary converter.
Roman Numeral Converter
Convert numbers to Roman numerals and Roman numerals back to numbers. Free, instant, in-browser converter (1–3999).
Random Number Generator
Generate random numbers in any range, with optional uniqueness, using the secure Web Crypto API. Free, instant, in-browser.
HTTP Status Codes
Look up any HTTP status code (200, 301, 404, 500…) with its meaning and category. Free, instant, searchable reference.
MIME Type Lookup
Find the MIME type for any file extension, or the extensions for a MIME type. Free, instant, searchable reference.
CSS Gradient Generator
Create linear and radial CSS gradients visually and copy the code. Free, instant, in-browser gradient generator.
CSS Box Shadow Generator
Design CSS box-shadows visually with sliders and copy the code. Free, instant, in-browser box-shadow generator.
Cron Expression Explainer
Explain a cron expression in plain English and see its next run times. Free, instant, in-browser cron parser.
JSON to YAML Converter
Convert JSON to YAML and YAML back to JSON instantly. Free, private, in-browser converter with validation.
Regex Tester
Test regular expressions against your text with live match highlighting and capture groups. Free, instant, in-browser regex tester.
Barcode Generator
Generate barcodes (CODE128, EAN, UPC and more) from any text and download as PNG. Free, instant, in-browser.
cURL Converter
Convert a cURL command to JavaScript fetch and Python requests code for free, in your browser. Paste curl, copy the code — safe for commands with tokens.
JSON to TypeScript
Generate TypeScript interfaces from JSON for free, in your browser. Paste JSON, get typed interfaces with nested types inferred.
Code to Image
Turn a code snippet into a clean, shareable image for free. Themes, backgrounds and a window frame — rendered in your browser, no upload, no sign-up.
SERP Preview Tool
Preview how your page appears in Google search results. Test title tags, meta descriptions and URLs — see exactly what users see. Free, in-browser.
Robots.txt Generator
Generate a robots.txt file for your website. Add allow and disallow rules, sitemap URL and crawl delay — free, in-browser, instant.
Ethereum Unit Converter (ETH / Gwei / Wei)
Convert between ETH, Gwei and Wei instantly with exact BigInt precision. Essential for Ethereum developers, gas calculations and smart contract work. Free, in-browser.
Password Strength Checker
Check how strong your password is with real-time scoring, entropy estimation and actionable improvement tips. Free, in-browser — your password never leaves your device.
HTML to Markdown Converter
Convert HTML to clean Markdown instantly. Paste HTML, get formatted Markdown — free, in-browser, private. Supports headings, links, images, lists and code blocks.
PPI & Screen Resolution Calculator
Calculate pixels per inch, dot pitch and display resolution from screen size and pixel dimensions. Free, in-browser.
RGB to HEX Color Converter
Convert RGB, HSL and HEX color values instantly with a visual preview. Free, private, in-browser.
Excel to CSV Converter
Convert Excel (.xlsx) spreadsheets to CSV format for free, right in your browser. No upload, no sign-up — extract all sheets or pick one.
JSON Validator & Linter
Validate JSON with detailed error messages showing line and column numbers. Format, minify and lint JSON — free, instant, in-browser.
CSS Minifier & Formatter
Minify CSS to reduce file size or beautify messy CSS with proper indentation. Free, instant, in-browser CSS optimizer.
HTML Preview / Sandbox
Write HTML, CSS and JavaScript and see a live preview as you type. Free, instant, in-browser HTML sandbox — no upload, no sign-up.
Morse Code Converter
Convert text to Morse code and Morse code back to text instantly. Play Morse code audio or copy the result. Free, in-browser, no upload.
SQL Formatter
Format and beautify SQL queries with uppercase keywords and clean indentation, or minify to one line. Free, instant, in-browser SQL formatter — no upload.
XML Formatter & Validator
Validate XML and pretty-print it with 2-space indentation, or minify it to one line. Free, instant, in-browser XML formatter — no upload, no sign-up.
Color Contrast Checker
Check WCAG color contrast between text and background — exact ratio plus AA/AAA pass/fail for normal and large text. Free, instant, in-browser checker.
CSV to Excel Converter
Convert CSV files or pasted CSV text to Excel (.xlsx) for free, right in your browser. Handles quoted fields and embedded commas — no upload, no sign-up.
XML to JSON Converter
Convert XML to JSON and JSON back to XML instantly, with attributes, arrays and clear errors. Free, private, in-browser converter.
Color Palette Generator
Generate complementary, analogous, triadic and monochromatic palettes from any base colour. Free, instant, in-browser — click any swatch to copy.
IP Subnet Calculator
Free IP subnet calculator: enter an IPv4 address and CIDR prefix to get the network, broadcast, usable host range, masks and IP class. Instant, in-browser.
AI Token Counter & LLM Cost Calculator
Count tokens in your prompt and estimate API cost across GPT, Claude and Gemini — with editable per-model pricing. Free, runs in your browser.
Which ferramentas para desenvolvedores tool should I use?
- Encode or decode Base64 → Base64 Encode / Decode
- Inspect a JSON Web Token → JWT Decoder
- Format and validate JSON → JSON Formatter & Validator
- Generate a secure random password → Password Generator
- Create a QR code from a link → QR Code Generator
About these ferramentas para desenvolvedores
A toolbox for everyday development: encode and decode Base64 and URLs, format and convert JSON/CSV/YAML, decode JWTs, generate hashes, UUIDs, QR codes and passwords, test regular expressions and look up HTTP status codes and MIME types. Each runs locally in your browser — safe for tokens, keys and other sensitive input — and pairs with a plain-English definition in our Glossary. Pick a tool above to get started, or browse the full A–Z index.
Frequently asked questions
Meu código ou dados são enviados?
Não — formatação, conversão e decodificação rodam inteiramente no navegador, seguro até para dados com tokens.