Drible

Drible is a set of 53 free tools for PDFs, images, text and code: merge, compress and sign PDFs, compress an image to an exact KB size, HEIC to JPG, remove backgrounds, format JSON and more. 48 of the tools run entirely in your browser, so the file never leaves your device; the 5 Office conversions use a server and delete the file right after converting. No signup, no watermarks. There is also a free photo and signature size chart for exams, passports and visas, checked against the official notices: https://drible.co/guides/photo-signature-size-chart