CoolUtils Online PDF Merger vs PDF24 Compare PDF

CoolUtils Online PDF Merger combines multiple files into one PDF in a browser, without signup or software installation. The free tool accepts up to five files per pass, with a limit of 50 MB per file. The order of the upload slots determines the sequence in the merged document. JPG, PNG and GIF images are accepted as well, with each image becoming a PDF page. CoolUtils says uploads and downloads use encrypted SSL/TLS connections and are processed in isolated environments. The product page says documents are used for merging and are not stored afterward; CoolUtils also says uploaded files and converted results are automatically deleted from its servers within 24 hours. The listed platform availability includes Android, iOS, Linux, macOS, web and Windows, though the primary platform is web. The online page does not list integrations, batch merging or page selection. CoolUtils recommends its desktop product for recurring or folder-level work and command-line automation.

PDF24 Compare PDF compares two versions of a PDF and marks text that has changed, been added, or been removed. Readers can view the documents side by side, as an overlay, or with a slider. The comparison runs directly in a browser without installation, and PDF24 says the files are not uploaded to its servers. Google Drive is listed as a file-selection option. Use is free, with no registration or time restrictions. PDF24 says transfers are SSL secured and server files are automatically deleted after one hour. For offline processing, PDF24 Creator keeps files on the local PC, but it can only be installed on Windows; Linux and Mac are not supported. PDF24 Tools can be installed from a browser on Android or iPhone and iPad, though it is not distributed through Google Play or the App Store. PDF24 says its online tools are available to companies free of charge and without restriction, and a data-processing agreement can be requested.