Reference · 18 original guides
Know what your files are doing
Practical explanations of the formats, compression trade-offs and failure modes behind the tools — written for people who want to know why something works before they click convert. Every guide links to the exact tools that apply, and every tool page links back to the relevant guides.
Format guides
What each file format is actually good at, and where it breaks.
- PDF vs Word: which format should you send?PDF · 6 minPDF freezes a document into pages; Word keeps it editable. The choice changes what the recipient can do with your file. This guide covers the trade-offs and why conversion is never a perfect copy.October 19, 2026
- HEIC vs JPG: which photo format should you keep?Image · 5 minYour iPhone saves HEIC while most cameras and websites expect JPG. One is smaller and stores more colour; the other opens everywhere. Here is how the two formats differ, and when converting actually helps.October 19, 2026
- GIF vs MP4: which should you use?Video · 5 minGIF is a tiny animated image format with hard limits; MP4 is compressed video that loops in a player. Understanding the difference explains why one is convenient and the other is small.October 19, 2026
- MP3 vs WAV vs M4A: audio formats comparedAudio · 5 minThe difference between MP3, WAV and M4A is not brand preference: it is compression versus compatibility. Here is how each one works and which job it suits.October 19, 2026
- Image formats explained5 minJPG keeps photos small, PNG keeps pixels exact, and newer formats such as WebP, HEIC and AVIF try to do both. Here is how to choose without overthinking it.October 17, 2026
- MP4 vs MOV5 minBoth are containers, not codecs, so switching between them does not have to cost quality. Here is when the difference matters and when it does not.October 17, 2026
Fundamentals
The concepts behind conversions: compression, containers, codecs, privacy.
- PDF passwords and permissions explainedPDF · 6 minA protected PDF can be locked in two very different ways. This guide separates the password you type from the permission flags behind it, and explains what unlocking a file actually changes.October 19, 2026
- Lossy vs lossless compression, explained5 minEvery quality slider is a trade between file size and fidelity. This guide explains both compression families, where each is used, and how to avoid losing the same quality twice.October 19, 2026
- Is it safe to upload? Browser privacy for file tools6 minA converter can call itself private while quietly uploading. This guide shows how to verify where the work happens, how to read a policy, and how to handle sensitive documents safely.October 19, 2026
- PDF format explained5 minPDFs keep every page fixed in place, which is why they look the same everywhere and why editing them is awkward. This guide explains what is actually inside the file.October 17, 2026
- Video codecs explained5 minA video file is two things: a container and the codecs inside it. Telling them apart explains most playback and conversion problems, from a phone that will not open a file to a browser that will not play one.October 17, 2026
Step-by-step how-tos
Short, practical walkthroughs for a specific file problem.
- PDF page management: merge, split, rotate, deletePDF · 5 minMost PDF editing tasks are page tasks: putting files in order, cutting out a chapter, turning a scan upright, deleting a blank sheet. This practical guide covers the workflow and the mistakes.October 19, 2026
- Favicon and ICO: a practical guideImage · 5 minA favicon is the smallest image on your site and one of the easiest to get wrong. Here is what browsers and operating systems really use, and how to build an icon that stays sharp.October 19, 2026
- Why your video won't play (and how to fix it)Video · 6 minPlayback failures usually come from the codec or the container rather than a damaged file. Here is a practical order for diagnosing the problem, and what conversion can and cannot fix.October 19, 2026
- How to convert HEIC to JPG5 minHEIC photos look great and confuse half the apps you send them to. Here are the reliable ways to get a JPG, whether you are on Windows, a Mac or a phone.October 17, 2026
- Compress a PDF without losing quality5 minPDF compression is a trade between file size and image detail. This guide explains where the megabytes come from and how far you can shrink a PDF before quality starts to show.October 17, 2026
Real-world use cases
Real situations — forms, email, job applications, sharing — and the tools that solve them.
- Photos for online forms and job applicationsImage · 5 minA photo fresh from your phone often breaks a form's rules. Here is a sensible order of operations for converting, cropping, resizing and compressing an upload, without damaging the original.October 19, 2026
- QR codes explained: capacity, errors and safe scanningDeveloper · 5 minA QR code is a small database disguised as a pattern. This guide covers the parts that decide whether it scans, what it can hold, and the risks to check before trusting one.October 19, 2026
Prefer to start with the tool?
Every tool page opens with the working tool, then explains its features, limits and privacy model — and links back to the guides that go deeper.