Remove text from PDF

GemBox.Pdf
4

GemBox.Pdf currently doesn’t have an API for “Find and Replace”, but we do intend to provide one in the future.
For now, can you try using something like this:

var page = document.Pages[0];
var pageContent = page.Content;
var texts = pageContent.GetText().Find("HELLO").ToList();

foreach (var text in texts)
{
    using var formattedText = new PdfFormattedText();
    formattedText.Append("Thanks");
    pageContent.DrawText(formattedText, new PdfPoint(text.Bounds.Left, text.Bounds.Bottom));
    text.Redact();
}