How to Summarise a Document with ChatGPT (Without Missing the Important Bits)

Short answer: attach the file to a ChatGPT chat (the paperclip or plus button), then tell it who the summary is for, how long it should be and what you need to pull out, such as decisions, deadlines or money. Ask it to quote the page or section for each key point so you can check them. Free accounts can upload documents, but only 3 files a day (OpenAI Help).

Can ChatGPT read a PDF or Word document?

Yes. ChatGPT accepts PDF, Word (DOCX) and plain text files, plus spreadsheets (XLSX, XLS, CSV) and PowerPoint (PPTX). This works on the free plan and on paid plans, on the web and in the mobile apps (OpenAI Help).

A Google Doc can't be uploaded directly. Download it as a PDF or Word file first (File, then Download), then upload that.

What are the limits?

OpenAI's help page sets out the main ones (OpenAI Help):

• Free accounts can upload 3 files a day.
• Documents can be up to 512 MB each, and text is capped at 2 million tokens per file. That's far longer than most reports, policies or contracts.
• Spreadsheets are limited to roughly 50 MB.

The prompt to use

Attach the document, then paste this and fill in the brackets:

Summarise the attached document for [who it's for, e.g. me, my manager, a parent with no background in this].
1. Start with a three-sentence overview in plain English.
2. Then list the key points as bullets, most important first.
3. Pull out every deadline, date, amount of money and action I need to take, in a separate list.
4. For each point, give the page number or section heading it comes from.
5. If anything is unclear or contradicts itself, say so rather than guessing.
Keep it under [300] words.

Points 4 and 5 do the most work. Page references let you check quickly, and permission to say "this isn't clear" stops ChatGPT smoothing over gaps.

How do I make the summary fit what I actually need?

Change the "for" line and the list in step 3. A few examples:

• A work report: "for my director, who has two minutes. Focus on decisions needed and risks."
• A letter from a school or a government office: "for a busy parent. What do I need to do, by when, and does it cost anything?"
• A rental lease or contract: "List what I'm agreeing to, any fees or penalties, notice periods and anything unusual." Treat this as a reading aid, not legal advice.
• A long article for study: "Summarise the argument, the evidence used and the main counter-argument, for a 15-year-old student."

If you summarise documents every week, saving these instructions as a skill means you don't retype them. The PDF report summary skill is written for Claude but works just as well pasted into ChatGPT.

Why does ChatGPT miss things in my PDF?

The common reasons:

• It's a scan, photo or chart. ChatGPT can read text and images in a PDF you attach to a chat, including charts and diagrams, but files saved as project files or GPT knowledge may not include embedded images (OpenAI Help). Blurry scans still cause misses. If it skips something, attach the PDF straight to the chat, or upload a clear photo of the page as an image.
• Your request is vague. "Summarise this" gives a generic overview. Saying what matters to you gets the right detail.
• The document is very long. Ask for a summary section by section, then a final summary of the summaries.

How do I check the summary is right?

Never forward or act on a summary of something important without a quick check:

1. Open the original at two or three of the page numbers it gave you and make sure the point is really there.
2. Ask: "What did you leave out of this summary that a careful reader might care about?"
3. Ask: "Quote the exact sentence that says [the deadline or amount]."
4. For legal, medical or money documents, use the summary to know what to ask, then check with the organisation or a professional.

Is it safe to upload documents?

Think before you upload anything private. On personal plans, your chats can be used to train OpenAI's models unless you turn off Improve the model for everyone in Settings, then Data controls. Temporary chats aren't used to improve the models, though OpenAI may keep them for up to 30 days for safety (OpenAI Help). Remove names, account numbers and other personal details where you can.

At work, follow your employer's rules. Don't upload confidential company or client documents to a personal account. OpenAI says it doesn't use content from business products such as ChatGPT Enterprise to improve its models (OpenAI Help).

Can I do this in Gemini or Copilot instead?

Yes, the same prompt works. In Gemini you can add a file to your message in the same way. Google uses its Lens technology to read text in images you add (Gemini Privacy Hub). The checking steps above apply whichever assistant you use.

Make it summarise your way every time

If you want summaries in your own format every time (always with deadlines first, say, or written for a particular reader), make a skill that knows how you like it. MakeASkill asks you a few quick questions and writes it for you, free. Make my summary skill