Limits by plan
Every ChatGPT attachment limit: 20 a message, 3 a day on Free
5 attachment caps stack: 20 per message, 3 a day on Free, 80 every 3 hours, per project, per GPT. A 30 second diagnosis for which one stopped you.
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102 guides, sorted by when we last checked the facts in them. Browsing by subject instead? Start here.
Limits by plan
What happens when ChatGPT's context window is full
The oldest part of the conversation stops being sent, with no error and no marker in the reply. What survives, what goes first, and the test that proves it.
Working with documents
12 ways to get better answers out of ChatGPT about your documents
12 tips, and the first is a 30 second check, because long files are truncated with no warning. Then how to force quotes and stop invented answers.
Limits by plan
Which ChatGPT plan reads images inside PDFs?
Only Enterprise gets visual retrieval for PDFs. Free, Go, Plus, Pro and Business extract text and discard images, which is why charts and scans return nothing.
What ChatGPT accepts
What file types can ChatGPT read in 2026? 7 fail silently
ChatGPT reads 4 file families and OpenAI publishes no extension list. 7 uploads go through cleanly and give it nothing to read, with the fix for each.
Limits by plan
ChatGPT file upload limit, free plan: 3 a day in 2026
ChatGPT Free: 3 file uploads a day, 500 MB Library storage, 5 files per project. What still works when you are out, and what Go at $8 changes.
Getting past the limits
How to bypass the ChatGPT file upload limit in 2026: 5 fixes
The limit cannot be raised, so all 5 fixes send less at a time. Paste in parts under 10,000 characters, plus the 4 tricks that only look like they work.
Error messages explained
ChatGPT file upload not working? Find your error here
Hit the limit having uploaded 1 file? Failed attempts count toward the 80 per 3 hours cap. Every ChatGPT upload error here, with the fix that clears it.
Error messages explained
Why ChatGPT forgets a file you already uploaded
Nothing deleted the file. The chat outgrew its context window, so the oldest content stopped being sent. Re-attach it, and the setup that stops it recurring.
Comparisons
Is ChatGPT Plus worth it for documents? 2 caps move, 5 do not
2 of the 8 upload caps move when you pay. The 2 million token cap that truncates long documents does not. Work out which wall you hit before spending $20.
Working with documents
How to work with many documents in one ChatGPT chat
Ten files in one conversation blur into one vague source. Label each on upload, order them deliberately, and know when to open a second chat.
Limits by plan
How long can a single ChatGPT message be? The 10,000 character rule
No published character cap, but paste over 10,000 characters and ChatGPT turns it into a file upload, spending an upload you never meant to spend.
Working with documents
How to get a Notion export into ChatGPT
ChatGPT does not open archives, and a Notion export is a zip of markdown files. Unzip it, join every page into 1 text file with headers, upload that.
Error messages explained
"You may only upload 1 file at a time" in ChatGPT
20 files per message is the web cap since February 2026, so this is a per message block, not your account or your quota. Send 1 per message, or bundle them.
Limits by plan
ChatGPT Plus raises 3 a day to 80 every 3 hours, and little else
Plus gives 80 files every 3 hours instead of 3 a day, plus 25 files per project. The 2M token cap is identical on every plan, so long files still get cut.
Working with documents
How to build a knowledge base in a ChatGPT Project
Free gets 5 project files, Plus 25, Pro 40. What belongs in project files, what to leave in a single chat, and why a smaller set gives sharper answers.
Limits by plan
How many files can you put in a ChatGPT Project? 5, 25 or 40
Free 5, Go and Plus 25, Pro and Business 40 files per project. OpenAI's own FAQ still prints 20 for Plus, and the project allowance is not your chat one.
Comparisons
Projects or custom GPTs for your documents?
Both hold files that persist. Projects hold more and stay personal, custom GPTs hold ten for life and can be shared. Which fits your documents.
Limits by plan
The ChatGPT storage limit: 25 GB, and the 500 MB one nobody mentions
25 GB per user, and a separate 500 MB Library cap on Free that bites first. Deleting old chats no longer frees either one, so here is what still does.
Limits by plan
What the business plans change about uploads, and what they do not
512 MB per file, 2M tokens, 25 GB per user: identical on Team, Business and Enterprise. Only Enterprise changes what ChatGPT can read inside a PDF.
Limits by plan
Does the ChatGPT upload limit depend on the model?
No. 512 MB per file and 2M tokens are checked at upload, before any model sees the file. The 1 row in 9 that the model does change, and what to change instead.
Error messages explained
"You have reached our limit of file uploads": the 2 causes
2 documented causes: failed uploads count toward the 80 per 3 hours cap, and 25 GB of storage never clears on its own. Deleting chats no longer frees it.
Limits by plan
When does the ChatGPT upload limit reset? 3 hours, rolling
OpenAI publishes no reset time for the Free cap of 3 a day. The general cap of 80 files rolls over 3 hours, freeing slots gradually, so an hour gets you moving.
Working with documents
Does OpenAI train on the files you upload to ChatGPT?
Consumer plans: yes, unless you switch it off in data controls. API and Enterprise are excluded. Files go in 30 days, but deleting the chat no longer does it.
Error messages explained
Why ChatGPT says "you can send up to -1 files"
A negative count is a display fault, not a real limit: your allowance minus whatever is already counted. 5 things push it under zero, and the fixes in order.
Limits by plan
How many knowledge files can a custom GPT hold? 10, for its lifetime
10 files per GPT, and that is a lifetime cap rather than per conversation. They also eat your 25 GB storage, and GPT creation has left personal accounts.
Working with documents
The 30 second check for whether ChatGPT read your whole document
Files past 2 million tokens are truncated with no warning. One question about the final page tells you how much ChatGPT really read, in 30 seconds.
Getting past the limits
Getting an email thread into ChatGPT without the noise
Copy the text, do not upload the .eml or .msg. Paste over 10,000 characters and ChatGPT makes it an attachment anyway. What to strip out of the thread first.
Limits by plan
How many files can you upload to ChatGPT? All 6 caps in one place
20 per message on web, 3 a day on Free, 80 every 3 hours, 10 per custom GPT. Six caps that stack, plus the one that never resets however long you wait.
Limits by plan
How many PDFs can you upload, and how many get read?
How many PDFs you can upload on Free, Plus, Pro, in Projects and to a custom GPT, plus the length cap that decides how much of a long PDF gets read.
Getting past the limits
5 free ways to get more file uploads out of ChatGPT
Free gives 3 uploads a day and the cap cannot be raised. 5 ways to spend fewer of them, including the one route that does not count as an upload.
Getting past the limits
How to send a PDF to ChatGPT
Paperclip on desktop, plus button on mobile, question in the same message. Then the one check that tells you whether ChatGPT read the whole PDF or just page 1.
Getting past the limits
How to split a long document for ChatGPT
Keep each part under 10,000 characters, cut at section boundaries, and send the wait-for-all-parts instruction first. Past 10,000 a paste becomes an upload.
Getting past the limits
How to upload large files to ChatGPT: 4 limits, 4 fixes
512 MB per file, 2M tokens per document, 3 a day on Free. Four separate limits stop a big file, and the one that stops most people shows no error.
Working with documents
How to keep a document in context in ChatGPT
There is no pin or lock for an attachment, so documents drop out of long chats silently. How to set the chat up, re-anchor when answers slip, when to restart.
Getting past the limits
Paste the text or upload the file?
Pasting is a message, not an upload, so no daily, rolling or storage cap touches it. But paste over 10,000 characters and ChatGPT converts it to a file anyway.
Getting past the limits
How to upload large code files to ChatGPT
Concatenate the 3 to 6 files that matter into 1 text file with path headers. ChatGPT never unpacks a zip. The one line command, and what to strip out first.
Getting past the limits
How to upload a large PDF to ChatGPT: 4 ways that work
512 MB is the ceiling, but a 3 MB PDF can still be too long: text caps at 2 million tokens. How to tell truncation from rejection, and the 4 fixes.
Getting past the limits
How to get more than 10 files into ChatGPT, now that a message takes 20
20 files per message on web since February 2026, not 10. Projects cap at 25 on Plus and a custom GPT at 10, plus the trick that sends 12 files as one.
What ChatGPT accepts
Which file format does ChatGPT handle best?
Plain text wins, because there is no parsing step to go wrong. All 9 common formats ranked, plus the 2 second test that spots a PDF ChatGPT cannot read.
What ChatGPT accepts
Pages, Numbers and Keynote files in ChatGPT
Not usefully. A .pages, .numbers or .key file stores its text as compressed binary. Export to Word, Excel or PowerPoint first, and here is which keeps most.
What ChatGPT accepts
Can ChatGPT read .eml and .msg email files?
EML reads fine, MSG does not: it is Outlook binary with no text layer. Save it as Text Only from Outlook, and why attachments never come out of either.
What ChatGPT accepts
Can ChatGPT read EPUB files? Yes, with 2 catches
Yes. An EPUB is a zip of HTML, so the text extracts cleanly. DRM stops you dead and book length breaks it quietly. How to convert one and split it by chapter.
What ChatGPT accepts
Why pasting a Google Docs link does not work
No. ChatGPT holds no Google session, so a Docs or Drive link returns a sign in page. The 30 second export route, and the format that keeps your tables intact.
What ChatGPT accepts
Can ChatGPT read log files?
Yes. Logs are plain text and upload fine up to 512 MB, but answer quality collapses far below that. The jq and grep lines that cut a log to what matters.
What ChatGPT accepts
Can you upload an MP3 or WAV file to ChatGPT?
No. OpenAI lists 4 upload families: text, spreadsheets, presentations, documents. Audio is in none of them. Transcribe it, and keep the speaker labels.
What ChatGPT accepts
ODT, HWP, PSD and other formats nobody documents
Yes, ODT uploads and reads fine. OpenAI publishes no extension list, so here is the test for any unusual format, and when exporting beats trying it.
What ChatGPT accepts
Can ChatGPT read RAR, 7z or tar archives?
No. RAR, 7z, tar and tar.gz are never unpacked, so 1 upload buys nothing. How to extract each format, handle split .part1 sets, and what to send instead.
What ChatGPT accepts
Can ChatGPT read RTF files? Yes, and the 1 case that fails
Yes. RTF is a document format and uploads like any other, inside the 512 MB and 2 million token caps. The 1 case that fails, and the 10 second fix for it.
What ChatGPT accepts
Can ChatGPT read SRT and VTT subtitle files?
Yes. SRT and VTT are plain text and upload like any other file. Strip the timestamps on anything feature length, since they take more room than the dialogue.
What ChatGPT accepts
Can ChatGPT read Word documents?
Yes, up to 512 MB per file, and DOCX is among the most reliable formats. Every plan but Enterprise discards the images, and how to spot what was dropped.
What ChatGPT accepts
Can ChatGPT open a ZIP archive?
No. ChatGPT never unpacks archives, so a ZIP costs 1 upload slot and returns nothing readable. Extract it, then bundle the files into 1 text file instead.
Comparisons
The best tool for a very long document: 3 approaches compared
3 approaches to a document too long for one upload: retrieval, a bigger context window, or splitting it. Which one fits depends on the question you ask.
Comparisons
ChatGPT API vs the web app for file uploads
The web app extracts text, retrieves the relevant parts and runs a Python sandbox, all inside the subscription. The API gives you none of it. What to rebuild.
Working with documents
How to get ChatGPT to cite pages and sections
Text extraction strips page breaks, so ChatGPT rarely knows the page. Ask it to quote the heading and the exact sentence, then search the PDF for that line.
Working with documents
How to compare two documents with ChatGPT properly
Uploading both files at once blends them into mush. Summarise each in its own chat, then compare the 2 summaries in a third, and attribution stays intact.
Error messages explained
Why ChatGPT says your conversation is too long
The chat is full, not the file. Messages, replies and uploaded files share one total, so the same file uploads fine in a new chat. How to move across cleanly.
What ChatGPT accepts
CSV and Excel limits in ChatGPT: about 50 MB, and no token cap
Spreadsheets cap around 50 MB and are exempt from the 2 million token limit that truncates documents. Why a 200,000 row CSV goes in when a report does not.
Working with documents
ChatGPT CV and resume review that is worth having
Ask for a review and you get praise. Ask it to argue for rejecting you, or to sit with 60 applications and 10 minutes, and the criticism finally arrives.
Limits by plan
Do the Mac and Windows apps have different upload limits? No, still 512 MB
512 MB per file and 3 uploads a day on Free apply identically in the Mac and Windows apps: one account, one pool. The one thing only a browser can do.
Working with documents
Why ChatGPT gives different answers about the same document
3 causes: silent truncation, sampling randomness and context eviction. How to tell which one you have in under a minute, and the question that separates them.
Working with documents
How to turn a document into slides with ChatGPT
Ask for a tab indented outline rather than markdown and PowerPoint imports it straight. One idea per slide, notes kept separate, and the prompt for both.
Working with documents
How to pull specific data out of a document with ChatGPT
Name every field, name the format, demand the source: "Return a CSV with columns date, party, amount". The 3 rules that stop ChatGPT filling gaps for you.
Working with documents
How to extract tables from a PDF with ChatGPT
Ask for CSV, 1 row per source row, values copied exactly, empty fields for empty cells. Then check it: a misread table comes back looking perfectly clean.
Working with documents
How to fact check a document with ChatGPT, and what it cannot do
ChatGPT has no source to consult, so its verdicts are guesses. Use it to extract and rank the claims that need checking, then the prompt that keeps it honest.
Error messages explained
ChatGPT says your file is too large. Which of the 4 caps did you hit?
4 caps produce this message: 512 MB per file, 50 MB spreadsheets, 20 MB images, 2M tokens of text. Under 10 MB means length, and compressing will not help.
Limits by plan
Can you upload files to ChatGPT on a phone?
Yes. The ChatGPT mobile apps use the same 512MB and 2 million token caps as the web, since limits belong to your account. What a phone cannot do, and the fix.
Error messages explained
ChatGPT file upload stuck loading? The 4 causes, and the 1 minute test
An upload that spins forever has 4 common causes. A 1 line text file in incognito tells you which one, in under a minute. Stop retrying: failed attempts count.
Comparisons
What a ChatGPT file uploader extension actually does
These extensions split a document into pieces ChatGPT accepts and send them in order. They cannot raise the 512MB cap or the Free 3 a day. How to judge one.
Working with documents
How to analyse financial statements with ChatGPT
Export the statements to CSV rather than uploading the PDF report. Spreadsheets are exempt from the 2 million token cap. Then check every figure it hands back.
Working with documents
How to make ChatGPT follow a document's structure
Extract the outline first, then hand it back as a template. Output arrives under your own section headings, in order, instead of one summary that flattens them.
Limits by plan
ChatGPT image upload limits: 20 MB, and why PDF pages count
20 MB per image is the size cap, and rarely what stopped you. The limit on how many is, and PDF pages count toward it. What resets it, and how to send less.
Working with documents
How to analyse a large JSON dataset with ChatGPT
JSON hits the 2 million token cap fast. Send the schema and a short sample, agree the approach, then convert tabular JSON to CSV, which is exempt from it.
Working with documents
Summarising a legal document with ChatGPT
Summarise a contract, judgment or policy clause by clause, never in one sweep. What ChatGPT locates reliably, and why 'no such clause' is never proof.
What ChatGPT accepts
Markdown, JSON, XML and code files in ChatGPT
Markdown, JSON, XML and code are plain text, so ChatGPT reads them cleanly up to 2 million tokens and 512MB. Why .md beats PDF and DOCX for a long document.
Limits by plan
ChatGPT max PDF size is 512 MB, so why does a 4 MB file fail?
512 MB is the hard ceiling and almost nobody reaches it. A 4 MB scanned PDF fails anyway, because a scan holds no text layer to extract. How to tell them apart.
Working with documents
How to get something useful out of a meeting transcript
Do not ask for a summary. Ask for 4 things: decisions, commitments with owners, open questions, disagreements. Keep the speaker labels or you lose every name.
Limits by plan
ChatGPT PDF page limit: none published, but 2M tokens caps it
OpenAI publishes no page limit. Size stops at 512 MB, length at 2 million tokens, and length truncates a PDF silently. The question that reveals how far it got.
What ChatGPT accepts
Can ChatGPT read PowerPoint PPTX files?
Yes, PPTX uploads work. But every plan except Enterprise strips the images out, so charts and diagrams never reach the model. Speaker notes usually do.
Error messages explained
ChatGPT cannot read your scanned PDF
Every plan except Enterprise extracts digital text and discards images, and a scan is all image. A 2 second test to confirm it, then the OCR route that works.
Error messages explained
The 3 causes of "something went wrong while analyzing your file"
The analysis step failed, not the upload, so file size is not the cause. 3 things explain almost every case. Retry once, test a 2 line file, then check yours.
Working with documents
How to actually revise from a textbook with ChatGPT
A chapter summary is the least useful thing to ask for. Upload the chapter and be tested on it instead, with worked examples and questions in exam format.
Working with documents
How to summarise a YouTube video with ChatGPT in 4 steps
ChatGPT cannot open a YouTube link or the video file, so use the transcript. 4 steps to pull it out and paste it in, plus what a text only view misses.
What ChatGPT accepts
Which image formats can you upload to ChatGPT, and the 20 MB cap
PNG, JPEG, WEBP and GIF all work, capped at 20 MB each. PSD, AI and RAW do not. Which to pick for a screenshot, and when text beats an image entirely.
Working with documents
How to translate a long document with ChatGPT
A translation runs as long as its source, so it needs 2x the room a summary does. Work section by section, and keep the glossary that stops 1 term becoming 3.
Error messages explained
ChatGPT will not accept that file type. Convert it, do not rename it.
ChatGPT rejects the format before anything uploads, so renaming the extension never helps. Convert to PDF, DOCX, TXT or CSV, and tell 3 refusals apart.
Comparisons
ChatGPT or Gemini for long documents?
ChatGPT caps document files at 2 million tokens and 512MB. Gemini publishes context windows per model, not per-file caps. Which suits your document, and why.
Comparisons
ChatGPT vs NotebookLM for working with documents
NotebookLM answers only from the sources you gave it and cites them. ChatGPT blends your document with what it already knows. Where each one lets you down.
Comparisons
ChatGPT or Perplexity for working with documents?
Perplexity searches the web and cites it. ChatGPT reasons over the file you hand it, up to 512MB and 2 million tokens. Which fits depends on where files live.
Working with documents
Getting a whole website into ChatGPT, page by page
Pasting a URL gets you 1 page, and only when browsing works. Save each page as text, flatten them into one upload with URL headers, and quotes stay traceable.
What ChatGPT accepts
Can you upload an MP4 or other video to ChatGPT?
Video is not among the 4 file families OpenAI lists for uploads. Transcribe it and upload the .txt instead, plus what to do when the visuals are the point.
Working with documents
How to analyse a whole book with ChatGPT
Text files cap at 2 million tokens, so a full book will not fit in one go. Work chapter by chapter with a running notes file, and know when to stop.
Getting past the limits
How to shrink a file so ChatGPT will accept it
Export to plain text first: a 40 MB Word file of screenshots lands in tens of KB. Then compression, image stripping, CSV, and the case where none of it helps.
Getting past the limits
How to upload a large Excel file to ChatGPT
Excel is capped at about 50MB but exempt from the 2 million token cap. Export to CSV, cut the columns you do not need, and send a sample if it is too big.
Getting past the limits
How to upload a large PowerPoint to ChatGPT
The cap is 512 MB per file, and a heavy deck is heavy because of images ChatGPT discards anyway. Export the slide text and speaker notes, and see what goes.
Getting past the limits
How to upload a large ZIP file to ChatGPT past the 512 MB cap
ChatGPT caps any single file at 512 MB, and a 700 MB archive is never 700 MB of text. See what is inside, pick the few files that matter, send them as one.
Getting past the limits
How to upload a scanned document to ChatGPT
ChatGPT extracts no text from a scan, so run OCR first: Preview on a Mac, PowerToys on Windows, OCRmyPDF for anything long. The 2 checks that catch bad OCR.
Comparisons
How to pick a ChatGPT Chrome extension without regretting it
Most ChatGPT extensions do 1 of 5 things, so name your problem first. The 15 second permission check rules out the risky ones before you read a feature list.
Working with documents
Using ChatGPT for contract review
3 things it does reliably: plain-English translation, spotting missing clauses, finding one-sided terms. 4 it cannot. Plus the data setting to check first.
Working with documents
Reading research papers with ChatGPT
Upload a paper and ChatGPT praises it. The prompts that turn it on the methodology instead, the statistics it gets wrong, and where to stop trusting it.
Working with documents
How to summarise long documents with ChatGPT
Anything past 2 million tokens is cut off silently, so run the last section test before you read the summary. Then the prompts that stop it coming back bland.
Comparisons
ChatGPT or Claude for document analysis? Length is what decides it
ChatGPT caps a document at 2 million tokens and Claude holds more at once. Where ChatGPT still wins is spreadsheets, and where it loses, no workaround helps.