Developer Guides
Practical, in-depth articles that explain the concepts behind our tools.
MD5 vs SHA-256: Differences, Security and When to Use Each
Compare MD5, SHA-1, SHA-256 and SHA-3: how hash functions work, why MD5 is broken, speed, checksums, HMAC and the right way to hash passwords.
Read guideBarcode Types Explained: EAN-13, UPC, Code 128, ITF-14, QR and More
A guide to the most common barcode symbologies, what each encodes, where it is used, check digits, GS1 numbers and how to choose the right barcode.
Read guideQR Code Best Practices: Size, Contrast, Error Correction and Testing
How to create QR codes that scan reliably in print and on screens: minimum size, quiet zone, colours, error correction levels, static vs dynamic codes and security.
Read guideNaming Conventions: camelCase vs snake_case vs kebab-case vs PascalCase
A practical guide to naming conventions across JavaScript, Python, Go, SQL, CSS, URLs and environment variables, with rules for acronyms and API boundaries.
Read guideCron Expression Examples: 30 Schedules Explained (with Pitfalls)
Learn cron syntax field by field and copy 30 tested cron expressions for every N minutes, weekdays, monthly jobs, business hours and more, plus time zone pitfalls.
Read guideBase64 Explained: How It Works, When to Use It and When Not To
A clear explanation of Base64 encoding: the algorithm, padding, URL-safe Base64, data URLs, size overhead, Unicode pitfalls and security misconceptions.
Read guideUUID v4 vs UUID v7 vs ULID: Which Unique ID Should You Use?
Compare random UUID v4, time-ordered UUID v7 and ULID for database keys, APIs and distributed systems, with performance, privacy and format trade-offs.
Read guideUnix Timestamp Explained: Seconds, Milliseconds, Time Zones and 2038
What Unix time is, why systems use it, how to convert timestamps in every major language, and how to avoid time zone, millisecond and Y2038 bugs.
Read guideRegex Cheat Sheet: Patterns, Flags and Real-World Examples
A practical regular expression cheat sheet with character classes, quantifiers, anchors, groups, lookarounds, flags and tested patterns for everyday tasks.
Read guideHow JWT Works and How to Decode a Token Safely
Understand the structure of JSON Web Tokens, how signatures are created and verified, common claims, security pitfalls and how to decode a JWT.
Read guideHow to Compress an Image to 100 KB Without Visibly Losing Quality
A step-by-step method to shrink photos below 100 KB for forms, email and the web: resize first, choose the right format, then tune quality.
Read guideJSON to TypeScript Interfaces: A Practical Guide to Typing API Responses
Learn how to turn JSON into accurate TypeScript interfaces, handle optional fields, nulls, unions and arrays, and keep types in sync with real APIs.
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