OCR a scanned PDF, and leave the picture as it was
Searchable, and the picture left alone
Drop a scanned PDF on the OCR page, choose its language or let the page find it, and read it. Each page that is only a picture is drawn at 300 dots per inch and read, and the words it is sure of go under the picture, each where its ink is, so a search lands on the word and a selection copies it. The picture itself is not touched: every image of the file you dropped comes across byte for byte, and that is checked before the searchable copy is offered. A page that already has its own text is left as it was.
Sure, or said
A wrong word under a scan is worse than none: a search finds the wrong place, and a copy carries a mistake nobody typed. So a word read with too little confidence is left out rather than guessed, and the result says how many were left out on each page. A page on which nothing can be read with confidence is given no words at all, and is named as unreadable. When no page can be read, nothing is made, and you are told why.
Languages
Choose the language, or let the page find it: it looks at the writing first — Latin letters, Cyrillic, Greek or another script — and then tries the languages written in it. Albanian, English and the other languages of the region are among them, and an accented letter read comes out as that letter, not as a dot or a question mark. How well a language is read was measured on invented pages for a few of them; every other is read, not measured.
The text, too
The same reading gives the text: as it reads, a column after another, or laid out as the page has it; and, for a page that is clearly a table, a CSV for a spreadsheet, whose cells can never run a formula. PDF to text says more.
Make a PDF searchable now — it opens the tool, with nothing to install.
The record
Reading changes nothing in the file you drop. A searchable copy is a new file, and its record says that a text layer was added, in which language, what became of each page and how many words were left out, and that the original picture is preserved. The text is kept with the file it was read from, and deleted with it or whenever you delete the reading; your account's trail says what was read and how many words, never the words. Files of up to 50 pages are read, at the size your plan uploads, and deleted after 90 days, or whenever you erase them. What a download costs is on the pricing page.