Short, specific answers to the file problems people hit most — no sign-up, no upload, and a free tool at the end of every one.
Why PDFs get so large, what compression actually removes, how to pick a level, and the three cases where compressing won't help at all.
What HEIC is, why Windows and older apps refuse to open it, how to convert a whole batch at once, and how to stop your iPhone shooting HEIC in the first place.
More guides are on the way. In the meantime, browse the full tool library or check the FAQ.