01
Open the document
Open a PDF that contains extractable text, then choose Translate in the sidebar. For image-only pages, create a searchable copy first with the OCR guide.
GrayCat PDF guide · macOS
Read a PDF and its translation side by side on Mac
Keep the source page on the left and its translation on the right. Translate one page or the whole document, edit the result, and save a side-by-side PDF.
Requires macOS 14.0 or later. Apple on-device translation requires macOS 15 or later. Scanned pages need OCR first.
Inside the app
Source and translation stay on the same page
Both sides move to the same page as you read. You can inspect and edit the translation without changing the source PDF.
GRAYCAT PDF
Source and translation stay on the same page
Steps
From opening a PDF to saving the translation
02
Choose a translation path
In Settings, choose Apple on-device translation or configure your own AI provider, OpenAI-compatible endpoint, or local Ollama service. Hosted providers normally require an API key.
03
Translate one page or the PDF
Select the target language. Use Translate Page for what you are reading now, or Translate PDF to process the document in page order.
04
Review, edit, and save
Edit the translation paragraph by paragraph. Progress is saved automatically; when ready, save a new PDF with source and translated pages side by side.
What to know before you start
The source PDF is not changed
Translation progress and edits are stored separately. Export creates a new side-by-side PDF.
Scanned pages need text recognition first
Translation requires extractable page text. If a page contains only an image, GrayCat PDF asks you to run OCR first.
On-device translation or a service you choose
Apple system translation processes text on device. For AI translation, only after you confirm does the text of the pages you translate, plus page context, go directly to the provider or endpoint you selected. GrayCat operates no relay server. API keys stay in the system Keychain.
The progress file contains source and translated text
Progress is kept in *.graycat-translation.json next to the source file or in Application Support. It is a local plaintext file that you can delete in Settings → Privacy. Password-protected PDFs do not create this plaintext progress file.
Read the GrayCat PDF privacy policy for the complete scope, or visit support for setup help.