Tools
Generators, validators and utilities. Almost everything runs in your browser: nothing you type leaves your computer. The ones that query an external service (postal code and exchange rates) say so.
By using the tools, you agree to the terms of use.
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Mark up to 10 tools with ☆ Add to favorites, on each tool's page: they show up here, on the home page and in the header.
Brazilian documents
- CNPJ (numeric and alphanumeric) Generate, validate and format Brazilian company IDs, including the new format with letters (Jul 2026). Runs in your browser
- CPF Generate and validate Brazilian taxpayer IDs, and see the issuing tax region. Runs in your browser
- Postal code (CEP) lookup Brazilian address from a CEP, via ViaCEP (with BrasilAPI as backup). Queries an external service
- PIS / PASEP / NIT Generate and validate Brazil's PIS, PASEP, NIT or NIS worker number (same calculation). Runs in your browser
- Mercosur license plate Convert an old Brazilian plate to the Mercosur format (and back) and validate it. Runs in your browser
- NF-e access key Validate the 44-character access key of Brazilian e-invoices (NF-e, NFC-e, CT-e, MDF-e) and see what each part means. Runs in your browser
- Boleto: digitable line Validate a Brazilian bank boleto's digitable line or barcode and see bank, amount and due date. Runs in your browser
- Pix copy-and-paste Read and check a Pix copy-and-paste code, or generate a static one with key, amount and reference. Runs in your browser
- Card number validator (Luhn) Check a card number's check digit with the Luhn algorithm, to test payment forms and systems. Runs in your browser
Everyday developer tools
- Gherkin to Playwright Test scenarios in plain language (for POs and QA) become automated Playwright tests (for developers). Runs in your browser
- Lorem Ipsum and placeholder text Placeholder text for layouts and for testing field limits: Latin Lorem Ipsum or excerpts from Machado de Assis, as plain text, HTML or Markdown. Runs in your browser
- ERP and legacy system dates Convert YYYYMMDD, Excel/Delphi serial, Clarion, JD Edwards Julian, Unix and boleto due factor. Runs in your browser
- UUID v4 and v7 Unique identifiers. v7 starts with the time and sorts by creation. Runs in your browser
- Hash (SHA) SHA-1, SHA-256, SHA-384 and SHA-512 of a text. Runs in your browser
- Base64 Encode and decode Base64 (and base64url), accents included. Runs in your browser
- JWT reader Shows a token's header, payload and validity. Runs in your browser
- JSON: format and validate Indents, minifies and points out syntax errors. Runs in your browser
- Text: count and transform Character and word counter, upper and lower case, remove accents, sort lines, remove duplicates and more. Runs in your browser
- Password generator Strong passwords drawn in your browser, with your choice of length and character types and the strength in bits. Runs in your browser
Configuration
- Dockerfile generator Multi-stage, rootless Dockerfile with a healthcheck for Spring (Maven or Gradle), Node, SPA and Python, plus the .dockerignore. Runs in your browser
- Docker Compose generator Build a compose.yaml with app, database, cache and proxy, with the good practices explained in comments. Runs in your browser
- Web server generator: nginx, Apache and Caddy The same answers become nginx, Apache and Caddy configuration, side by side: proxy, SPA, PHP, HTTPS and security headers. Runs in your browser
- robots.txt generator and tester Build your site's robots.txt (blocking AI robots if you want) and test whether a robot may visit an address, by the official rules. Runs in your browser
- Web app generator: manifest and icons Turn your site into an app people can install on phones and computers: manifest, icons (including Android's maskable and the iPhone one) and the <head> lines, in a .zip. Runs in your browser
General tools
- Image compressor and metadata viewer Shrink JPEG, PNG and WebP and see (or erase) what a photo says about you: camera, date and GPS location. Runs in your browser
- Date and business-day calculator Calendar and business days between two dates, add or subtract days, with Brazil's national holidays and your local ones. Runs in your browser
- Numbers in words (Portuguese) and Roman numerals Write numbers in Brazilian Portuguese words: in reais (checks, contracts, receipts), cardinal (vinte e três), ordinal (vigésimo terceiro), or as Roman numerals (MMXXVI). Runs in your browser
- Percentage and rule of three What is X% of Y, X is what % of Y, increase and discount, value before a markup, and direct and inverse rule of three. Runs in your browser
- Number and name picker Draw numbers in a range (with or without repeats) or names from a list, using the browser's cryptographic generator. Runs in your browser
- Exchange rates: dollar, euro, Bitcoin and 8 more currencies US dollar and euro (commercial and PTAX), Bitcoin and the PTAX of pound, yen, Swiss franc and others, with source and time. Queries an external service
- Currency converter 12 currencies, PTAX for any date since 2000, real cost with IOF and spread, and the last 90 days chart. Queries an external service