Understand how page copying differs from image conversion when merging PDFs, and check selectable text without assuming every document feature survives.
Check the source text first
Open a source PDF and try selecting a short sentence. If selection works, the page likely contains a usable text representation. A scanned page may instead contain only an image, in which case selecting the photographed words will not work.
Merging does not perform OCR. Image-only source pages stay image-only unless another application adds a text layer. Do not describe a merged scan as searchable merely because it now sits beside pages that contain selectable text.
Use page copying rather than image export
ToolNivo Merge PDF copies pages from the selected sources into a new document. It does not intentionally rasterize every page into a JPEG. Ordinary page text and page dimensions can therefore be retained through the merge.
Choose the source files, arrange them and generate the result. Avoid first converting a text-based PDF into screenshots if your goal is to keep its text. That extra conversion would remove the advantage of copying the original PDF pages.
Review more than text selection
Being able to select words is only one part of document behavior. Bookmarks, forms, attachments, signatures and document-level accessibility structure are not guaranteed to be preserved by this tool. A PDF that looks similar may still behave differently in a viewer.
If a source contains interactive fields or relies on a particular navigation structure, inspect those features separately. For documents whose original signed or structured state must remain intact, keep and distribute the original files when appropriate instead of treating the merged copy as equivalent.
Verify the actual download
Open the result and select text from each source section. Copy a short sample into a plain text editor to check whether it remains meaningful. Also inspect images, page orientation and the joining boundaries. The combined file is a new document; successful creation alone does not prove that all source behavior survived unchanged.