Developer Tutorials

Original tutorials built around the tools on this site, updated regularly.

• The Complete JSONPath Syntax Guide: From Basics to Real-World Use

  A systematic tour of JSONPath: root node, child keys, wildcards, recursive descent, filter expressions, and array slicing — with practical API debugging examples.

  WebTool Team · 2026-09-01

• JWT Explained: Structure, How It Works, and Common Misconceptions

  Breaking down the three-part Header/Payload/Signature structure of a JWT, how signature verification works, what the standard claims mean, and why decoding is not verification.

  WebTool Team · 2026-08-28

• MD5 vs SHA-256: How to Choose a Hash Algorithm

  Comparing MD5, SHA-1, SHA-256, and SHA-512 on digest length, current security status, and where each fits — with a decision table for picking one.

  WebTool Team · 2026-08-20

• Crontab Syntax Cheat Sheet and Ten Everyday Examples

  The five-field crontab format explained, ten expressions that cover 90% of use cases, and classic pitfalls like the day-of-month vs day-of-week OR behavior.

  WebTool Team · 2026-08-15

• How Base64 Encoding Works: Why Does the Output Grow by 33%?

  Where Base64's 64 characters come from, how 3 bytes become 4 characters, what the trailing equals signs mean, and two frequent pitfalls: Base64URL and mojibake with non-ASCII text.

  WebTool Team · 2026-09-04

• The Complete Guide to Unix Timestamps: Seconds vs. Milliseconds, Time Zones, and the Year 2038 Problem

  What a Unix timestamp is and where the epoch starts, how to tell seconds from milliseconds at a glance, what time zones really mean, the 2038 overflow problem, and how to get the current timestamp in every major language.

  WebTool Team · 2026-09-04

• How to Choose an AES Mode: Why ECB Is Unsafe, and How CBC Differs from GCM

  The famous penguin picture explains ECB's pattern leakage, a comparison of CBC/GCM/CTR on security and performance, plus practical advice on key length, IV usage, and padding.

  WebTool Team · 2026-09-04

• Regular Expressions for Beginners: 20 Handy Patterns and Four Debugging Tricks

  A regex metacharacter cheat sheet, 20 ready-to-use patterns for emails, phone numbers, URLs, and more, plus debugging tips for greedy matching and runaway backtracking.

  WebTool Team · 2026-09-04