Developer Utilities

JWTs look like scrambled text but are just three base64url-encoded segments. Learn their structure, how to decode one safely, and why decoding is not the same as verifying.

Base64 turns binary data into plain ASCII text, at the cost of about 33% more size. Here is how the encoding works, a real example, and the situations where you genuinely need it.

A single-line SQL query with nested joins is nearly impossible to review. Learn how SQL formatting rules work and how a formatter turns dense queries into readable, maintainable code.

Banks approve loans based on income ratios, not wishful thinking. Learn how to work out the home price you can realistically afford.

Nested JSON does not drop neatly into spreadsheet rows and columns. Here is how JSON to CSV conversion actually works, and where it gets tricky.

Your JSON-LD looks valid but Google still refuses rich results. Learn the four error categories that fail the Rich Results Test: missing required properties, bad nesting, wrong value types, and duplicate schema blocks.

Master structured data: Learn how to implement JSON-LD, Microdata, and RDFa schemas using Schema.org specifications for search engine rich results.

UPC, EAN, Code 128, QR — not all barcodes are interchangeable. This guide breaks down the most common barcode formats, what each one is built for, and how to pick the right one for your product or workflow.

Adding custom colors and branding logos to your QR codes can dramatically increase scan rates. Here is how to design beautiful, high-performing QR codes without breaking scan reliability.

QR codes come in two types: static and dynamic. Learn the key differences between them, how destination redirect tracking works, and how to select the right type for your project.

Print business cards are making a high-tech comeback. Learn how to embed a digital contact card (vCard) directly into a QR code so clients can save your contact details in a single scan.

Want to create a custom QR code for your website, Wi-Fi network, or business card? Follow this comprehensive, step-by-step guide to design, style, and export a high-performing QR code using Toolio's Free QR Code Generator.