klzth – Simple, Secure PDF Merging Online

klzth（merge PDFs locally in browser） is a browser-based PDF merger that lets you combine multiple PDF files quickly and easily, without uploading your documents to a server or creating an account. Arrange files in your preferred order, merge pages while preserving selectable text and original image quality, and optionally resize mixed page sizes to a consistent A4 format. With no watermark, no subscription, and affordable one-time licences, klzth makes PDF merging simple, private, and accessible on Windows, Mac, and other modern devices.