Features & Guide

Getting Started

After installing PhantomAI from the Chrome Web Store, click the extension icon in your browser toolbar. You will see a sign-in screen. Click "Sign in on phantom-ai.app" to create an account or log in.

Once signed in, you will see your email, current plan, and daily query count. All features are now active on every webpage you visit. No setup or configuration needed.

If you ever get signed out, just open the extension popup and sign in again. Your settings and documents are saved to your browser and will still be there.

Highlight

This is the simplest way to use PhantomAI. It works on any webpage.

1. Highlight any text on the page by clicking and dragging over it, just like you would to copy something.
2. Press the highlight key (default: ]). That's it.

PhantomAI sends the highlighted text to AI and shows you the answer as floating text at the bottom of your screen. The answer disappears automatically after a few seconds.

This works everywhere: Google Forms, Canvas, Blackboard, Coursera, Wikipedia, PDFs open in Chrome, and any other webpage.

Capture

Some questions are not just text. They include images, diagrams, math equations, charts, or things you cannot highlight. Capture mode handles these.

Using the keyboard

1. Press the capture key (default: \).
2. An indicator appears at the bottom-right of the screen. Your screen enters capture mode.
3. Click and drag a box around whatever you want AI to look at.
4. Release the mouse. PhantomAI captures that area and sends it to AI.

Using the mouse only

1. Triple-click on any empty space on the page (not on text).
2. Your screen enters capture mode. Drag a box around the question or image.
3. Release to send it.

Press Esc at any time to cancel capture mode without sending anything.

The AI reads everything inside your selection box: text, images, diagrams, handwriting, math notation, and more.

Paste

After you get an answer from any query (highlight or capture), PhantomAI remembers it. You can paste it into any text field on the page.

1. Click into a text field where you want the answer to go (a form input, a text box, a search bar, etc.).
2. Press the paste key (default: [).

The answer gets inserted into that field. If you have Type Mode turned on (it is on by default), the answer types out character by character instead of appearing all at once.

You can paste the same answer multiple times into different fields. It always pastes your most recent AI answer until you make a new query.

Reference Images

Sometimes you want AI to see extra information every time you ask a question. For example, a formula sheet, a reference table, or notes from a previous page. Reference images let you do this.

1. Press the reference key (default: ').
2. Drag a box around whatever you want to save as a reference.
3. Release. The screenshot is saved.

You can save multiple reference images. From now on, every query you make (highlight or capture) will include these reference images so AI can see them alongside your question.

To clear all saved reference images, press Shift + the reference key. You can also clear them from the Files tab in the extension popup.

You can see how many reference images you have saved by opening the extension popup and going to the Files tab.

Context Documents

You can upload files that AI will use as background knowledge when answering your questions. This is useful for study guides, lecture notes, or any reference material.

How to upload

1. Open the PhantomAI extension popup.
2. Go to the Files tab.
3. Drag files into the drop zone, or click it to browse your computer.

Supported file types

• PDF - the text content is extracted automatically
• TXT - plain text files
• MD - Markdown files
• CSV - spreadsheet data

Once uploaded, the AI automatically searches your documents for relevant information every time you ask a question. You do not need to do anything special. If your documents contain an answer or useful context, AI will use it.

You can remove individual documents by clicking the X next to them, or clear everything with the Clear All button.

Answer Text Settings

These settings control how AI answers look on your screen. Open the extension popup and go to the Settings tab to find them.

Screen Capture Settings

These settings control the capture experience. Open the extension popup and go to the Settings tab, under Screen Capture.

Hotkeys

PhantomAI uses four keys for its main actions. Each one defaults to a single key press, but you can set any of them to a key combination (like Cmd+A or Ctrl+Shift+K) if you prefer.

To change a key: click the key button in the extension popup, then press the key or key combination you want. The change saves automatically. Avoid keys that conflict with browser shortcuts.

Plans & Limits

PhantomAI offers three plans. All plans have access to every feature. The only difference is how many AI queries you can make per day.

Query counts reset every day at midnight UTC (7:00 PM Eastern / 4:00 PM Pacific). You can see your current count in the extension popup.

You can upgrade, downgrade, or cancel your plan at any time from the Account page or through the extension popup.