Guides
Practical explainers for getting the most out of tomai.uk tools.
Our guides explain how tomai.uk tools work, how to keep your data private, and how to pick the right tool for your task. Each guide is written for real users, not search engines, and stays up to date as the site grows. Start with the privacy guide if you want to understand what happens to your files. We keep the advice practical and concise so you can act on it immediately, whether you are converting a file, checking a website, or automating a workflow.
How tomai.uk handles your data
What stays in your browser, what goes to the server, and how long we keep it.
How to choose the right tool
A simple guide to picking the right free tool on tomai.uk by task type.
JSON vs YAML vs XML: choosing the right format
Three data formats, three personalities. When strictness, human editing, or document structure matters — and how to convert between them safely.
How IP blacklist and proxy detection actually works
Datacenter ranges, abuse histories, shared egress and fingerprints — what IP purity means and why innocent users sometimes get flagged.
Unix timestamps: the four traps that break your dates
Seconds vs milliseconds, UTC vs local time, DST shifts and locale parsing — where timestamp bugs come from and how to avoid them.
Base64 is encoding, not encryption — five myths worth dropping
No key, no secrecy, a third more bytes, and a URL-safe twin: what Base64 actually does and the mistakes people keep making with it.
What a JWT leaks — and why not to paste production tokens online
Signatures prevent tampering, not reading: the payload is readable by anyone, the pitfalls of alg=none, and how to inspect tokens safely.
The meta tags that actually matter for SEO
Title length, description that earns clicks, canonical, robots, social cards and hreflang — a working checklist, not folklore.
Regex Handbook: Patterns You Will Actually Reuse
A practical field guide to regular expressions: literals, character classes, anchors, groups, lookarounds, flags and the backtracking traps that freeze pages.
UUIDs Explained: v1 vs v4 vs v7 and When to Use Each
What UUID versions actually differ in, why v7 exists for databases, how likely collisions really are, and when a plain counter beats them all.
Hash Functions Compared: MD5, SHA-1, SHA-256 and CRC32
Checksums versus password hashing, which algorithms are broken for security but fine for file integrity, and how to verify a download in seconds.
Cron Reference: the Five Fields, Special Characters and Gotchas
Minute to weekday in one page: field ranges, steps, lists, presets, the day-of-month versus day-of-week OR quirk, and how to preview next runs.
How to Merge and Split PDF Files for Free
Merge, split, rotate and reorder PDF pages in your browser — no upload, no signup.
BaZi Chart Reading: What Your Four Pillars Mean
Birth date plus hour maps to eight characters — here is how to read the chart before asking AI.