You want to turn your saved files, notes, and web clippings into a searchable reference that answers questions using only your data. Perplexity Spaces let you upload documents, paste text, and set custom instructions so the AI retrieves answers exclusively from your content. This article explains how to create a Space, upload files, configure search behavior, and avoid common mistakes.
Key Takeaways: Setting Up a Perplexity Space as a Custom Knowledge Base
- Create a Space from the sidebar: Click the + New Space button to start building your custom knowledge base.
- Upload files or paste text: Use the Add Files button or paste text directly into the Space to populate it with your data.
- Set custom instructions: Write a system prompt that tells Perplexity to only answer from the uploaded content, not from the public web.
What Is a Perplexity Space and Why Use It as a Knowledge Base
A Perplexity Space is a dedicated container where you store files, text snippets, and links. When you ask a question inside a Space, the AI searches only the content you have added. This turns the Space into a private, custom knowledge base that never pulls from the open internet unless you allow it.
The Space uses the same underlying search and summarization engine as Perplexity’s main search bar, but the scope is limited to your uploaded material. This is useful for research projects, internal documentation, client onboarding guides, or any scenario where you need consistent answers based on a fixed set of sources.
Prerequisites include a Perplexity Pro subscription because Spaces are a Pro feature. You also need the files or text you want to use in a supported format: PDF, TXT, DOCX, PPTX, XLSX, or CSV. Each Space supports up to 500 files with a total size limit of 500 MB.
Steps to Create and Configure a Perplexity Space as a Custom Knowledge Base
Method 1: Create a Space from the Sidebar
- Open the Space sidebar
On the left side of the Perplexity web app, locate the Spaces section. Click the + New Space button. - Name the Space
Type a descriptive name such as “Q3 Product Docs” or “Client Onboarding Guide.” This name appears in the sidebar and in search results. - Set the search scope
Below the name, find the dropdown labeled Search Scope. Choose “Only my files” to force the AI to answer exclusively from your uploaded content. If you select “Web + my files,” the AI will also search the public internet. - Add custom instructions
In the text box labeled Instructions, write a system prompt. Example: “You are a research assistant. Answer questions using only the files in this Space. Do not use outside sources.” This prompt is applied to every query in the Space. - Upload files
Click the Add Files button and select one or more supported files from your computer. You can also drag and drop files directly into the Space window. After upload, each file appears as a source card with a filename and page count. - Add text or links manually
Below the file area, click Add Text or Link. Paste a URL or type a block of text. This content is treated the same as an uploaded file. - Save and test
Click the Save button at the top of the Space. Then type a question in the chat box that appears below the files. The answer should reference your uploaded content only.
Method 2: Create a Space from an Existing Chat
- Open a chat thread
Navigate to any previous Perplexity conversation where you have uploaded files or used specific sources. - Click the three-dot menu
In the top-right corner of the chat window, click the three-dot menu icon. Select “Create Space from this Chat.” - Name and configure
The new Space inherits the files and instructions from the chat. Rename it if needed and adjust the search scope as described in Method 1. - Save and test
Click Save. The Space appears in your sidebar with all the original files and instructions.
Common Mistakes and Things to Avoid
“The AI answers from the web even though I selected ‘Only my files’”
This happens when the custom instructions conflict with the search scope setting. Go to the Space settings and confirm that Search Scope is set to “Only my files.” Also check the Instructions box for any phrase that tells the AI to search the web, such as “use the internet” or “look up recent data.” Remove such phrases and save again.
“Uploaded files do not appear in answers”
Perplexity indexes files after upload. Large files may take a few seconds to process. If a file still does not appear, check that it is in a supported format: PDF, TXT, DOCX, PPTX, XLSX, or CSV. Encrypted or password-protected files are not supported. Re-upload the file in a plain format.
“The Space runs out of file capacity”
Each Space has a 500 MB total file limit and a 500-file limit. If you exceed either, uploads will fail. Delete old or duplicate files from the Space by hovering over a file card and clicking the trash icon. For larger collections, split content across multiple Spaces and give each a distinct name.
“Answers are too generic or miss details”
The AI may summarize broadly if your files contain very long documents. Break large PDFs into smaller chapters or sections before uploading. Also refine your custom instructions. Instead of “use only my files,” write “use only the files in this Space and quote specific page numbers when possible.”
Perplexity Free vs Pro: Space Features and Limits
| Item | Free Plan | Pro Plan |
|---|---|---|
| Spaces creation | Not available | Unlimited Spaces |
| Files per Space | N/A | Up to 500 files |
| Total storage per Space | N/A | 500 MB |
| Custom instructions | N/A | Yes |
| Search scope control | N/A | Only my files / Web + my files |
| AI model selection | N/A | Choice of GPT-4, Claude, or Perplexity models |
You can now create a Perplexity Space, upload your documents, and configure it to answer questions from your private data only. Start by naming a Space and setting the search scope to “Only my files” to prevent web results from leaking in. For advanced control, write precise custom instructions and split large files into smaller chunks before uploading.