Practical guides for everyday file and data tasks

Understand the formats behind the tools, choose the right workflow, and avoid common mistakes before converting or editing your files.

What Is JSON? A Plain-English Guide

What JSON is, what it looks like, and why every API speaks it.

Trailing commas, single quotes, unexpected tokens — and how to fix each one.

The same data in all three formats, and how to choose between them.

Every way to open, view and edit .json files on any device.

Naming, structure, dates, numbers and nulls — conventions that save pain later.

Every regex token that matters — classes, quantifiers, groups, anchors and lookarounds — with examples.

How Base64 turns binary into text, why it's everywhere, and why it isn't encryption.

UUID versions explained, collision odds, and when to use v4 vs v7 for database keys.

Free ways to encrypt a PDF on any device — no Acrobat needed — and how strong each one is.

Fill forms and add your signature to any PDF free, in the browser — no Acrobat, no uploads.

Which image format to use when: quality, transparency, file size and browser support compared.

Get image files small without visible quality loss: formats, quality settings and workflow.

CSV explained: how the format works, how to open and edit one, and how to keep Excel from mangling it.

Lossless vs lossy audio explained: quality, file sizes, and when each format is the right pick.