Most free PDF sites make you upload your file to a stranger's server. Fylevia doesn't — 15 of its 16 tools run entirely inside your browser tab: merge, split, sign, watermark, crop, OCR, PDF to Word, images to PDF, QR codes. The file never travels. The 16th is Compress, which really does need a server. We say so on the page, hold it in memory only while it runs, and write nothing to a database. It also shows the real output size before you download — measured, not estimated. Free. No account.