How to search for text inside PDF files on Windows

You know the document exists. You remember a phrase from it, maybe a client's name or a line from page 12, but not what the file was called or which folder it ended up in. The search box in File Explorer is built around file names, so typing that phrase usually gets you nothing useful.

What you need is a search that reads the text inside the PDFs. This post shows how to do that with Chatda, a free search app for Windows 10 and 11 (it runs on macOS too), and what to check when a PDF still refuses to show up.

First, check that the PDF has text in it

Some PDFs are really photos of paper. A scanner or a phone app saved each page as a picture, and there are no letters in the file for any search tool to read.

Open the PDF and try to select a sentence with your mouse. If you can highlight words, the text is there and it can be searched. If the whole page highlights as one block, or nothing highlights at all, the page is an image. You'll only find that file by its name.

Set up the search once

Download Chatda from the download page and install it. Installing asks for administrator approval, because Chatda installs for all users together with its drive indexing service.

Chatda isn't code-signed yet, so Windows SmartScreen may say it doesn't recognize the app. The download page lists the file's SHA-256 checksum and shows how to compare it in PowerShell. If the value matches, choose More info, then Run anyway.

On Windows, Chatda adds every fixed drive (C:\, D:\ and so on) by itself. For a whole drive it only keeps file names, sizes and dates, so you can find any file by name right away, but not by what's written inside it.

To search inside documents, add the folders where they live:

Click All locations ▾ at the top.
Choose + Add folder and pick a folder, for example Documents or Desktop.
Indexing starts on its own. The status bar at the bottom shows the progress and the time left.

Chatda reads the text of PDF, Word, Excel, PowerPoint, HWPX, TXT, Markdown and CSV files. Other formats can still be found by name. If your PDFs are on a NAS, use Connect network folder in the same panel and enter the address, your username and your password.

Search for the phrase

Type a word or two into the search box. You don't need to press Enter: results show up as you type, usually within 0.2 seconds.

Each result has a Content column that shows where your words appear in the document. If it's empty, the file matched by its name only. Click a result once and the preview panel on the right shows the text of the PDF (for PDFs up to 30 MB). Double-click to open the file in your usual PDF reader.

A few things make a big difference when you're hunting for one document:

Content only. In the Search in dropdown, switch from "Name + content" to Content only. Files that merely have your word in their name drop out, and you're left with the ones where the word is inside the document.
Exact phrases. Put the words in quotes, like "payment statement", to find them together and in that order.
Only PDFs. Add *.pdf to the search, or tick PDF in the All types ▾ list. contract *.pdf finds PDFs that contain "contract".
Leave a word out. contract -draft hides results that contain "draft".
Recent files. The Date dropdown can limit results to today, the past week, month or year. Sorting by Recently modified puts what you worked on lately at the top.

If you're not sure of the exact wording, start short. Two distinctive words usually find more than a long sentence you half remember.

New and changed PDFs

You don't have to re-index after saving a file. In a local folder Chatda picks up new and changed files within about half a second. On a NAS it can take up to five minutes. If you're in a hurry, choose Re-index from the folder's menu.

When a PDF still doesn't show up

Go through these in order:

Is the text selectable? If the page is a scanned image, there's nothing to search inside it (see the first section).
Is the folder added by itself? A file that is only covered by a whole-drive entry like C:\ is searched by name only. Add its folder with + Add folder.
Is the mode right? Try Content only and a shorter, more general word. Searching for bottleneck finds more than approval bottleneck.
Is it really a PDF? Check the extension. Formats outside the list above match by name only.
Did indexing finish? A ⚠ mark in front of a folder means indexing didn't finish. Choose Re-index from its menu.

The help page explains every filter and search operator, and the FAQ covers the questions that come up most.