Which tool should I use?
Decode JWTs without sharing tokens. Diff two snippets before a commit. Encode Base64 payloads. Humanize cron for ops and CI.
Client-side developer tools. Fast, private, no upload.
Free utilities for debugging, QA and everyday engineering — plus a dedicated Brazilian tools hub (CPF, CNPJ and more) with full Portuguese explanations. Every calculator and decoder runs in your browser; we do not require an account.
Geradores e validadores brasileiros (CPF e mais) — área em português.
Format and validate JSON online. Sister tool — private, client-side, free.
Count characters, words, lines, paragraphs and UTF-8 bytes as you type.
Parse URLs into parts and compare two links to spot query and path differences.
Live side-by-side preview with formatter, highlighting and mobile frames.
Inspect header and payload locally. Your token never leaves the browser.
Convert JSON arrays to CSV tables and CSV back to JSON.
Beautify messy SQL with indentation and keyword highlighting.
Test regular expressions live and explain each token.
Turn curl into Fetch, Axios, Python, Go, PHP or C#.
Compare two texts or code blocks with clear additions and deletions.
Encode or decode text safely with Unicode support.
Build cron expressions or turn 0 0 * * * into plain English.
Generate UUID v4 / GUID values. Bulk create, format and validate locally.
Every tool runs in your browser. No accounts, no server-side processing of secrets — ideal for JWT tokens, diffs and encodings.
DevsDrill is built as a lightweight static hub. Pages load quickly, tools share a consistent layout with clear privacy notes. Whether you are debugging an expired access token, comparing two tracking URLs, beautifying a messy SELECT, testing a regex against a production log line, or counting characters for a meta description, the workflow is the same: paste locally, get an answer, leave without creating an account.
We also publish long-form help on each tool page — how it works, when to use it, FAQ and privacy notes — so the site is useful as a reference, not only as a blank form. Brazilian developers can open the Ferramentas Brasil area for CPF/CNPJ generators and validators, string helpers and calculators, each with Portuguese articles and ethical-use warnings.
Decode JWTs without sharing tokens. Diff two snippets before a commit. Encode Base64 payloads. Humanize cron for ops and CI.
Developer utilities often handle secrets. DevsDrill never sends your inputs to our servers.
The English catalog under /tools/ covers universal developer chores. The Portuguese catalog under /pt/ focuses on Brazilian document formats and everyday text/math helpers. Both sides share the same privacy model: static pages, client-side JavaScript, transparent footers linking to About, Privacy and Contact (Portuguese aliases Sobre and Privacidade).
If you maintain test databases, onboarding forms or fiscal sandboxes, start with the Brazil hub. If you are wiring APIs, inspecting tokens or cleaning SQL, start with the cards above. Either way, read the on-page FAQ before pasting production secrets — and prefer fixtures over live customer data whenever possible.
Yes. Optional PayPal or PIX donations help keep the site online.
No. JWT, Base64, diffs and cron parsing happen entirely in your browser.
The main developer tools support English and Portuguese (PT) via the language switch. The /pt/ area focuses on Brazilian document generators and validators in Portuguese.
Email brunojfc@gmail.com for support, privacy questions or feedback. See the Contact page for topics we can help with.
If a tool saved you time, a tip helps cover hosting.
Pay with PIX using the random key below.
Donation to Bruno J F Costa