Inject prompts into PDFs in seconds. A lightweight, secure tool to add instructions, descriptions, or hidden prompts to your PDF metadata and content.
- 🔒 100% Client-Side: No files are ever uploaded to a server. All processing happens locally in your browser.
- Metadata Manipulation: Automatically modifies the "Subject" field of the PDF.
- 🫥 Invisible Text Injection: Adds a hidden text layer (opacity 0) on the first page, making it "invisible" to humans but readable by machines and AI scrapers.
- 🚀 Instant & Lightweight: No heavy dependencies; modify your documents in real-time.
The tool utilizes two primary methods to ensure your prompts are detected by AI systems:
- Subject Metadata: The prompt is inserted into the PDF's "Subject" field. Many PDF readers and AI indexing systems prioritize this field as the document's main description.
- Hidden Text Layer: By injecting text with 0% opacity on the first page, the prompt becomes part of the document's selectable text. This is ideal for targeting LLMs (Large Language Models) that "read" the text content without affecting the visual design.
- Security Testing: Researching Prompt Injection vulnerabilities in document-based AI workflows.
- AI Cataloging: Providing specific context or instructions to AI agents during document analysis.
- Hidden Watermarking: Adding non-visual metadata or descriptions for internal tracking.
- Open the application in your browser.
- Upload your PDF (remember: it stays on your machine!).
- Enter your desired prompt or instruction.
- Download the modified version instantly.
Note
Most modern AI systems and PDF parsers treat the "Subject" field as a primary source of context. This tool ensures your instructions are placed exactly where these systems look first.
Distributed under the MIT License.
Note on Attribution: You are free to use, modify, and distribute this software, provided that the original copyright notice and this permission notice are included in all copies or substantial portions of the software.
Copyright (c) 2026 [markeclaudio]