GrayCat PDF
Bilingual PDF Reader & Tools
Only for Mac
Free
Mac
GrayCat PDF is a free, native macOS PDF toolbox built for bilingual reading.
TRANSLATION AT ITS HEART
• Side-by-side page translation: original and translation displayed together, page by page
• Instant translation: select any text while reading to get a translation, term explanations, and a context-aware rendering
• Editable results: machine translation is only a starting point — refine it paragraph by paragraph, and your edits are saved automatically
• Resume anytime: close the document and reopen it later; translation progress is restored exactly, so long papers can be read across sessions
• Two engines: Apple on-device translation on macOS 15+ (macOS may download language assets), or bring your own AI model (DeepSeek, OpenAI, Claude, Gemini, Kimi, Qwen, GLM, local Ollama, and more) — your API key is stored only in this Mac's Keychain and sent only to your configured provider to authenticate requests
• Export a bilingual PDF that combines the translation with the original
READING EXPERIENCE
• Continuous, single-page, and two-page modes; outline sidebar; drag-to-reorder page thumbnails
• Full-text search, quick page jumps, complete dark mode support
• Switch the interface between English and Chinese at any time
A COMPLETE PDF TOOLBOX
• Merge and reorder PDFs, images, Word/RTF, and text files; extract page ranges; insert blank pages
• Reduce file size with an explicitly warned rasterized copy, created only when the result is smaller
• OCR scanned documents into searchable copies
• Highlight, underline, strikethrough, sticky notes, handwritten signatures
• Set or remove passwords; clear title, author, subject, and keyword properties before sharing
• Export to images, Word (tables preserved), or plain text
• Batch processing: compress, OCR, or clear basic document properties for whole queues
• A real save model: ⌘S, Save As, and close prompts — your edits never vanish silently
LOCAL-FIRST, PRIVACY-RESPECTING
• No GrayCat account, no ads, no analytics SDKs — the developer operates no document server and receives no document content
• Your documents stay on your Mac; only when you explicitly use AI translation is your selection, or the text of the pages you translate, plus page context sent to the provider you chose, after consent
• Password-protected PDFs never get plaintext translation caches
Free to download. Start reading bilingually today.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Translation is now more reliable and easier to verify.
• Translation blocks stay aligned with their original PDF regions; incomplete, filtered, empty, or malformed results are rejected.
• When using a third-party AI provider, dense pages are translated in smaller batches with progress and cancellation.
• Retries and cancellation no longer overwrite existing edits or translations. For unencrypted PDFs, saved translation projects preserve results for each target language.
• Long translations use a complete-page fallback when possible. Export stops before any text would be clipped.
• Recent Files now hides same-path documents that are already open in tabs.
• Fixed Two/Single page mode after switching documents, menu localization, search, undo, signature placement, and several stability issues.
The developer, 泳涛 茅, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Linked to You
The following data may be collected and linked to your identity:
- User Content
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- 泳涛 茅
- Size
- 1.4 MB
- Category
- Productivity
- Compatibility
Requires macOS 14.0 or later.
- Mac
Requires macOS 14.0 or later.
- Mac
- Languages
- English and Simplified Chinese
- Age Rating
4+
- 4+
- Copyright
- © 2026 Yongtao Mao