GUIDES
Background for the work between the tools.
Short, practical explanations of the formats and problems the tools handle. Every guide links to the related tools so you can act on it immediately.
Merge, split, and reorder PDFs without uploading themHow local browser PDF editing works, when to split or extract pages, and what document features are not preserved.JPG, PNG, or WebP: choosing the right image formatHow the three common web image formats differ, which one to export, and when converting between them helps or hurts.Cleaning messy CSV data in the browserA practical pass over duplicate rows, filters, sorting, column selection, and CSV to JSON conversion.JSON validation, formatting, and JSON LinesWhat a validator actually checks, why formatting is safe, and when JSON Lines is the right shape for your data.Base64, URL encoding, and HTML entities explainedThree encodings that are constantly confused, what each one is for, and the mistakes that cause broken data.What a Content-Security-Policy header actually doesHow directives and fallbacks resolve, why a policy does not fix injection by itself, and how to roll one out safely.Cron expressions: reading and building schedulesThe five fields, the day-of-month and day-of-week quirk, and how to check a schedule before it runs in production.Text cleanup: whitespace, duplicates, and invisible charactersWhy two identical-looking strings fail to match, and the safe order of operations for cleaning a list.
Prefer to get straight to work? All tools are listed on the home page.