Are my files sent to a server?
Files are converted in your browser. The name, email and message you type into the contact form are sent to Web3Forms when you press the send button. Keep these two flows apart.
If I enter 3, 1 for a PDF, do the pages come out in reverse?
No. Selected pages are de-duplicated and sorted into the original order. Enter positions counted from the first page, not the page numbers printed inside the PDF.
I compressed an image but the size stayed the same.
If compressing to the same format as the original gives a larger result, the original is saved instead. Files that are already compressed, and PNGs, may not shrink much just by changing the quality value.
Can you compress PDFs or run OCR?
Dedicated PDF compression and OCR are not offered. You can extract the pages you need or resize at the image stage, but these are not the same features.
Can I convert to MP3 or MP4?
There are separate MP4→MP3 and MOV→MP4 tools. The general audio workspace outputs WAV and the general video workspace outputs WebM, with limits depending on your browser and codecs.
Will every device give the same result?
File size and supported codecs can vary with the browser’s image and media encoders and the device’s memory. Keep your originals and check the results.