Blog
Guides & tutorials
Practical articles on developer utilities, data formats, calculators, and text workflows. Each guide links to free tools on Utilitoo you can use immediately - no signup, most processing happens in your browser.
POSIX to BCP 47 Locale Conversion Pitfalls
Why en_US.UTF-8 is not the same as en-US, how Accept-Language quality weights work, and how to convert locale strings for HTML, JavaScript Intl, and shells.
Read article →Bcrypt vs SHA-256 for Passwords
SHA-256 is a checksum, not a password store. See unsalted hash failures, how bcrypt salt and cost work, and how to check hashes in the browser.
Read article →YAML to JSON Conversion Pitfalls
Why YAML-to-JSON conversions fail in CI and Kubernetes workflows - indentation, types, multiline strings, and what to check before you paste the result into an API.
Read article →Timezones and DST Pitfalls for Schedulers
Why fixed UTC offsets fail twice a year, how IANA zones work, and how to find meeting overlap across cities without spreadsheet errors.
Read article →Reading Unix Timestamps in Incident Logs
Seconds vs milliseconds, UTC vs local, and JWT exp claims - a practical guide to decoding Unix time during outages with free browser tools.
Read article →QR Codes vs Barcodes - When to Use Each (and How to Generate Them)
QR codes and barcodes solve different scanning problems. Learn formats, use cases, print tips, and free generators for URLs, WiFi, retail, and inventory labels.
Read article →Secure API Tokens and Secrets - A Developer's Guide
API keys, session secrets, and webhook tokens need real randomness. Learn token types, length, encoding, and safe generation with a free browser tool.
Read article →Home and Garden Tools on Utilitoo - Plan Beds, Mulch, and Colors in Your Browser
Introducing Utilitoo's Home and Garden category - color names from photos, plant spacing, mulch volume, and raised bed soil math. Free, browser-local tools for DIY gardeners and decorators.
Read article →Mermaid Editor and Viewer - Diagram as Code Without Installing Anything
Learn how to write, preview, and export Mermaid diagrams in the browser. Real examples for README files, architecture docs, and design reviews.
Read article →APR Explained - What It Means for Loans and Credit Cards
APR is on every loan offer but often misunderstood. Learn how it works, real examples for mortgages and cards, and how to compare rates with a free calculator.
Read article →How to View and Inspect CSV Files Online (Without Excel)
Learn when an online CSV viewer beats spreadsheets, with real examples for exports, QA, and quick data checks - plus a free browser-based tool.
Read article →How to Remove Duplicate Lines from Text (With Real Examples)
Duplicate lines show up in logs, email lists, and copy-pasted configs. Learn when and how to dedupe text safely with a free online tool.
Read article →ROI Calculator Guide - Measure Returns on Investments and Projects
ROI sounds simple but gets misused in marketing and side projects. Learn the formula, real examples, and how to calculate return on investment online.
Read article →How to Validate JSON Before Production
Broken JSON takes down deploys and APIs. Learn a practical validation workflow with examples from CI, webhooks, and config files.
Read article →JSON vs XML - Which Format Should You Use?
JSON and XML both carry structured data but fit different systems. Compare trade-offs with real API, config, and enterprise examples.
Read article →Base64 Encoding Explained for Developers
Base64 shows up in JWTs, data URLs, and email attachments. Learn what it does, when to use it, and common mistakes - with a free encode/decode tool.
Read article →How to Decode JWTs Safely (Without Trusting Them)
JWTs power modern auth but are easy to misread. Learn header, payload, and signature basics with dev-focused examples and a free decoder.
Read article →Why Browser-Local Tools Matter for Privacy
Many online utilities upload your data by default. Learn how browser-local processing protects API keys, documents, and personal text - with practical examples.
Read article →CSV to JSON - When and How to Convert Data
CSV feeds spreadsheets and SaaS exports; JSON feeds APIs. Learn when to convert between them, with examples from integrations and ETL prep.
Read article →