Guides
Practical explanations, examples, and references for the work you do with UtiliStudio.
Each guide explains a concept in plain language, shows real examples you can copy, and links to the tool that helps you put it into practice. New guides are added regularly.
JSON
- JSONPath cheat sheet: syntax and examplesEvery common JSONPath expression explained against one sample document, from simple property access to slices and filters, with notes on how implementations differ.4 min read
- JSON vs YAML vs TOML: which format should you use?The same configuration written three ways, with a clear comparison of readability, strictness, comments, and common pitfalls, so you can pick the right format for each job.4 min read
- Common JSON errors and how to fix themA practical reference for the JSON mistakes that break parsers, with a broken and fixed example for each, how to read parse errors, and how to stop them from happening.5 min read
APIs and HTTP
- CORS errors explained, and how to fix themWhat the same-origin policy and CORS actually do, why an API can work in curl but fail in the browser, and how to fix the most common CORS errors properly.4 min read
- HTTP status codes explained: a practical referenceA practical guide to the HTTP status codes you actually meet, grouped by class, with advice on choosing the right code for APIs and websites.4 min read
- JWT explained: structure, claims, and security pitfallsA clear explanation of JSON Web Tokens, from the three parts of a token to standard claims, signing algorithms, safe verification, and the mistakes that cause real vulnerabilities.4 min read
Writing
Productivity
UUIDs
- UUID v4 vs v7: which one should you use?Version 4 is random; version 7 starts with a timestamp so values sort by creation time. Here is how they differ and how to pick the right one for your system.6 min read
- How to generate a UUID in JavaScript, Python, Java, and SQLCopy-ready examples for generating version 4 and version 7 UUIDs in the languages and databases developers use most, plus how to validate and store them correctly.5 min read
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