How to Use AI With Your Files: PDFs, Screenshots, Spreadsheets

Summarize a lease, read a confusing error screenshot, chart a spreadsheet, and check the numbers yourself. Plus each chatbot's file limits, and what you should never upload.

Checked October 17, 2026. Researched and drafted with help from Grok Bot.

Quick answer

• Every major chatbot reads files now. Click the + (or paperclip) next to the message box, pick a file, and ask a question.
• PDFs, Word files, spreadsheets and screenshots all work in ChatGPT, Gemini, Claude, Grok and Copilot.
• Ask for proof. Tell the AI to quote the page or cell it used. Then check the important parts yourself.
• Free plans have tight limits. ChatGPT Free allows 3 uploads a day. Gemini Free reads less at once than paid plans.
• Never upload passwords, ID numbers, full bank or card numbers, or other people's private records.

File limits by chatbot

Chatbot	How to upload	Files at once	Size per file	Big-document note	Free plan
ChatGPT	+ by the message box	Up to 80 files every 3 hours	Docs 512 MB; spreadsheets ~50 MB; images 20 MB	Text up to 2 million tokens per file. Reads the text of PDFs, not the pictures inside (except Enterprise)	✓ 3 uploads a day; no audio
Gemini	Add files in the text box	Up to 10 per prompt	100 MB (video 2 GB)	How much it reads at once: Free 32k tokens, AI Plus 128k, AI Pro/Ultra 1 million (~1,500 pages)	✓
Claude	+ → Add files or photos	Up to 20 per chat	500 MB	PDFs up to 1,000 pages; charts and images read in PDFs up to 100 pages	✓
Grok	+ next to the message box	~100 on the web; 20 on Android	150 MB	Over 100 pages: focuses on text and key visuals	✓
Microsoft Copilot	+ → Add images or files	Up to 20 per conversation	50 MB	PDF, Word, Excel, PowerPoint, images, text, CSV	✓
Perplexity	Upload button in the search box	Weekly upload allowance	40 MB	—	✓ limited

What's a "token"? It's how AI measures text. Roughly, 1,000 tokens is about 750 words. A bigger number means it can read a longer document in one go.

Perplexity's limits come from a help page we could only see in search results. DeepSeek's upload limits are not published on a page we could check.

Never upload these

• Passwords, PINs or security answers
• Social Security, passport or driver's license numbers (or photos of the cards)
• Full bank account or credit card numbers
• Medical records you don't need help with
• Other people's private documents without their OK
• Work files your employer doesn't allow in AI tools

Tip: black out (redact) private numbers before you upload. On a phone, mark up a screenshot first. On a PDF, cover the number with a box, then print to a new PDF.

Which one should I use? The verdict

Quick questions

Can I upload a PDF to ChatGPT for free? Yes. ChatGPT Free accepts PDFs, but only 3 file uploads a day.

What's the best free AI to summarize a PDF? For long PDFs, Claude Free reads up to 1,000 pages. Grok and Copilot are also free and accept large files. Ask each to quote page numbers so you can check.

Can AI read my Excel spreadsheet? Yes. ChatGPT, Gemini, Claude, Grok and Copilot accept XLSX files. In Claude, you must first turn on code execution and file creation in settings.

Does AI read the pictures inside my PDF? It depends. Claude reads charts and images in PDFs up to 100 pages. ChatGPT reads only the text of PDFs on most plans.

Are my uploaded files private? Policies differ. Copilot says it keeps uploads for up to 18 months and doesn't train on them. ChatGPT may use files for training if Improve the model for everyone is on. Check each app's settings.

Before you start

• Sign in. File uploads need an account in most apps.
• Redact first. Cover private numbers before uploading (see the list above).
• Name your files clearly. "lease-2026.pdf" beats "scan0003.pdf." It helps you, and the AI, keep track.
• Know the free limits. On ChatGPT Free, plan your 3 daily uploads. Put several pages in one PDF instead of uploading them one by one.
• Privacy reminder: see our free guide AI Privacy and Fact-Checking (coming soon).

Job 1: Summarize a lease (PDF)

Prompt:

This is my apartment lease. Summarize it in 10 bullet points in plain English.
Then make a table of every fee, deadline and penalty: what it is, the amount or date, and the page number.
Then list anything unusual compared with a typical US lease, and say how sure you are.
Quote the exact sentence for anything about breaking the lease early.

What good looks like: page numbers for every fee, direct quotes, and an honest "not sure" where the lease is unclear.

Check it: open the PDF and look up 2–3 of the page numbers yourself. If one is wrong, say "Page [X] doesn't say that. Re-check."

Tip for Claude: use the PDF's page numbers as shown in your PDF viewer, not the numbers printed on the pages.

Job 2: Read a screenshot error

Take a screenshot of the error (on most computers: Windows + Shift + S on Windows, Cmd + Shift + 4 on a Mac), then paste it straight into the chat.

Prompt:

I got this error on my [laptop/phone/printer]. I'm not technical.
1. What does it mean, in one sentence?
2. Give me the safest fix first, in numbered steps, one action per step.
3. Tell me what NOT to do.
If the screenshot is hard to read, tell me what you can't see.

Safety: if a "virus warning" screenshot asks you to call a number or pay, ask: "Could this be a scam?" Real security warnings don't ask you to call a phone number.

Job 3: Chart a spreadsheet

Use a simple budget or sales sheet with clear column headers.

Prompt:

This spreadsheet has my monthly spending for this year. Columns: month, category, amount.
1. Total spending by category, as a table, highest first.
2. Make a bar chart of spending by month.
3. Which 3 categories grew the most from January to June? Show the numbers.
4. List any rows that look like errors (blank amounts, duplicates, very large numbers).

If the headers are unclear, tell the AI what each column means. It's the single biggest fix for wrong answers.

Gemini bonus: below a chart, tap Edit to change the chart type or labels, then Update.

Job 4: Check the numbers

AI can make math mistakes, especially with long tables. Ask it to check itself:

Recalculate the totals from the raw data, step by step. Show your work.
Then compare with your earlier answer. If they differ, tell me which is right and why.

And check one or two totals yourself with a calculator or your spreadsheet's SUM. If they match, you can trust the rest more.

Step by step: ChatGPT

1. In a chat, select + by the message box (or drag a file in).
2. Pick your file: PDF, DOCX, TXT, XLSX, XLS, CSV, TSV, PPTX or an image.
3. Type what you want, and send.

Good to know:

• Google Docs (.gdoc) can't be uploaded directly. In Google Docs, choose File → Download as PDF or DOCX first.
• Audio files (like a meeting recording) need a paid plan.
• PDF images: on most plans, ChatGPT reads the text in a PDF, not the pictures or charts inside it. For a chart, take a screenshot and upload that.
• Files stay in Library: deleting a chat doesn't delete a file saved in Library. Open Library, select the file, and choose Delete.
• Projects hold up to 5 (Free), 25 (Go/Plus) or 40 (Pro) files. See I5.

Step by step: Gemini

1. Go to gemini.google.com and type your question.
2. Click Add files, then Upload Files (or Add from Drive).
3. Click Submit.

Good to know:

• Up to 10 files per prompt. Files up to 100 MB each; videos up to 2 GB.
• Free plans read up to 5 minutes of video and 10 minutes of audio total. AI Pro and Ultra stretch that to 1 hour of video and 3 hours of audio.
• "Your uploads may be too large for the best results" means the file is bigger than your plan reads at once. Upload a smaller file or split it.
• "Delete data to upload file" means Gemini's own storage is full. Delete old activity in Settings & help → Activity.
• Drive files: you need Keep Activity on and Google Workspace connected.

Step by step: Claude

1. Click + in the lower left of the chat box.
2. Select Add files or photos, choose files, and click Open. Or drag them in, or paste an image.
3. Ask your question.

Good to know:

• Up to 20 files per chat, 500 MB each. Images up to 8000 × 8000 pixels.
• PDFs up to 1,000 pages. Claude reads text and charts in PDFs of 100 pages or fewer. From 101 to 1,000 pages, it reads text only.
• Spreadsheets (XLSX): turn on code execution and file creation in your settings first. CSV works without it.
• Word and other non-PDF files: text only. Images inside them aren't read.
• Want files available in every chat on a topic? Add them to a Project (30 MB each).

Step by step: Grok

Grok handles a wide mix of files in one go: documents, spreadsheets, code, images, audio and video, which makes it a strong everyday choice for "here's everything, help me make sense of it."

1. In any chat, click or tap + next to the message box.
2. Select files (or drag and drop on the web). You can attach several in one message.
3. Wait for Grok to confirm the upload, then ask.

Good to know:

• Web: up to about 100 files at once. Android: up to 20. iOS: multiple.
• Most files up to 150 MB.
• Types: PDF, DOCX, TXT, CSV, XLSX, PPTX, HTML, JSON, Markdown and more; JPEG, PNG, WebP, HEIC; MP3, WAV, M4A; MP4, MOV.
• For PDFs over 100 pages, Grok focuses on text and key visuals. Refer to pages by their actual page numbers.
• Images inside non-PDF files may not be read.
• Free up space: go to grok.com/files to delete uploads.

Step by step: Microsoft Copilot

1. Press the Open icon (+) and select Add images or files.
2. Pick your file. It appears as an attachment.
3. Ask your question, like "What recommendations would you give based on this document?"

Good to know:

• Up to 20 files per conversation, 50 MB each.
• Types: PDF, DOCX, XLSX, PPTX; PNG, JPEG; TXT, JSON, CSV, MD.
• Microsoft keeps uploaded files for up to 18 months, then deletes them, and says it doesn't use them for model training.
• Conversation full? Start a new one to add more files.

The others

Common mistakes and fixes

Problem	Likely cause	Fix
"File type not supported"	Unusual format (.gdoc, .pages, .heic on some apps)	Export or save as PDF, DOCX, XLSX or PNG
"Upload limit reached" (ChatGPT)	Free 3/day, or 80 per 3 hours	Wait, or combine pages into one PDF. Failed uploads can count too
"Too large"	Over the size or page limit	Split the file, or upload just the pages you need
Summary misses a table or chart	App read text only	Screenshot the chart and upload the image, or use Claude for PDFs of 100 pages or fewer
Wrong totals	Unclear headers, or AI math slip	Explain the columns; ask it to recalculate step by step; check one total yourself
Page numbers don't match	Printed vs PDF page numbers	Ask for "PDF page numbers," or quote the sentence instead
Answer includes things not in the file	AI filled gaps	Add: "Use only this file. If it's not there, say so."

Prompt pack

Use only this file. If the answer isn't in it, say "not in the file." Quote the page or cell for every fact.

Summarize this in 5 bullets for someone who has 1 minute. Then list 3 things I need to do and by when.

Make a table of every date, dollar amount and name in this document, with where you found each one.

Compare these two files. What changed between version 1 and version 2? Use a table.

This is a screenshot of [what]. Explain what I'm looking at, in plain English, and what I should do next.

Check this spreadsheet for errors: blanks, duplicates, totals that don't add up, and numbers that look out of place.

Explain this document like I'm new to the topic. Then give me 5 questions to ask [a landlord/doctor/accountant] about it.

Next level

• I5: ChatGPT Projects and I4: AI Projects Explained keep your files in one place across chats.
• A4: Connect AI to Your Gmail, Calendar and Drive (Advanced, coming soon) lets AI read files straight from your accounts, with a safety box on permissions.
• AI Privacy and Fact-Checking (free beginner guide, coming soon).