Free PDF Editor is a browser-based PDF highlighter and editor. Upload a PDF, highlight or underline the text you need, and download a clean file — free, with no signup and no watermark. Highlighting runs locally in your browser by default, so your document stays on your device. It works on desktop and mobile, including scanned PDFs, and accepts PDF, DOCX, XLSX, PPTX, CSV, JPG, PNG, GIF and WebP files.