Updated August 31, 2026. The short answer is that there is no single “file limit” for ChatGPT, Claude, or Gemini. Each service combines different rules for how many files you can attach at once, maximum size per file, how many can remain in a project or persistent knowledge base, context-window capacity, storage quota, and rolling usage limits. That is why the same file set may work in one tool and fail in another — or work in a chat but fail when you try to turn it into persistent knowledge.
To choose the right tool, separate four questions: how many files you want to attach now, how large the biggest file is, which formats are in the set, and whether those files need to remain available across future conversations.
Summary: the limits that most affect the choice
| Tool | Chat upload | Size per file | Project/persistent knowledge | Format highlights |
|---|---|---|---|---|
| ChatGPT | Up to 20 files in one web message, according to the February 2026 release notes | 512 MB hard general limit; text/documents also have a 2-million-token cap; spreadsheets are around 50 MB; images, 20 MB | Projects: 5 files on Free, 25 on Go/Plus, and 40 on Edu/Pro/Business/Enterprise according to the dedicated Projects page | Documents, spreadsheets, presentations, text/code, and images; video attachments can be available through supported paths, but are handled separately from still-image inputs |
| Claude | Up to 20 files per chat | Up to 500 MB per file in chat | Project files: 30 MB per file; file count is described as unlimited, but total content must fit within the project/context capacity | PDF, DOCX, CSV, TXT, HTML, ODT, RTF, EPUB, JSON, XLSX with code execution enabled; JPEG, PNG, GIF, and WebP |
| Gemini | Up to 10 files in the same prompt, subject to availability | Video: up to 2 GB; other supported types: up to 100 MB | Gems accept knowledge files, but the Gems page does not publish a separate total cap as clearly as ChatGPT; Google points to its general upload rules | Documents, spreadsheets, images, audio, video, ZIP, and one code folder or GitHub repository with up to 5,000 files and up to 100 MB |
Primary sources: ChatGPT release notes, OpenAI file-upload FAQ, Projects in ChatGPT, Claude file uploads, Claude projects, Gemini uploads, and Gems in Gemini.
ChatGPT: the limit is not just 512 MB
In ChatGPT, 512 MB per file is the hard general ceiling published by OpenAI, but that does not mean every 500 MB file will be accepted and fully analyzed. Text and document files also have a 2-million-token limit per file. Spreadsheets and CSV files have a practical cap of about 50 MB, depending on row size, while images are limited to 20 MB per image.
For file count, OpenAI announced in February 2026 that ChatGPT on the web can attach up to 20 files in a single message. This is different from Project limits and from custom-GPT knowledge limits. So “I can attach 20 now” does not mean “I can keep 20 as permanent knowledge in every workspace.”
ChatGPT Projects: official pages currently disagree
The dedicated Projects in ChatGPT page checked for this article states 5 files per project on Free, 25 on Go/Plus, and 40 on Edu/Pro/Business/Enterprise, with no more than 10 files uploaded at once. However, the general file-upload FAQ still shows 20 files per project on Plus and 40 on higher plans. Because the two official pages are inconsistent, this comparison uses the dedicated Projects page as the primary reference and records the discrepancy rather than pretending it is resolved.
There are also limits you will not see by looking only at the project. The upload FAQ states a rate of up to 80 files every 3 hours for users generally and 3 file uploads per day on Free, with the possibility of lower limits during peak hours. OpenAI also warns that failed upload attempts may count toward the upload-rate limit.
ChatGPT Library also has its own storage. The file storage and Library page currently lists 500 MB for Free, 4 GB for Go, 20 GB for Plus and Business, and 100 GB for Pro. That storage is separate from daily/attachment limits, so an upload can still fail even when the individual file is well below 512 MB.
Claude: 500 MB in chat, but 30 MB per project file
Claude has a particularly important distinction between chat and project uploads. Its upload documentation lists up to 20 files per chat and 500 MB per file. Project files, however, are limited to 30 MB per file. A 120 MB PDF may therefore work in a chat but be ineligible as a persistent project file.
Anthropic describes the number of project files as unlimited, with one decisive condition: total content still has to fit within Claude's context/project capacity. In other words, “unlimited” does not mean infinite capacity. Many small files can exhaust the available knowledge capacity before any file counter blocks you. Projects can also use retrieval mechanisms to expand practical capacity as project knowledge grows.
Large PDFs have a second layer of limits
Claude limits PDFs to 1,000 pages. For PDFs up to 100 pages, Claude can analyze both text and visual elements; from 101 to 1,000 pages, the documentation says processing becomes text-only and visual elements are not analyzed. A PDF can therefore be accepted by megabyte size while still losing part of its multimodal analysis because of page count.
Documented formats include PDF, DOCX, CSV, TXT, HTML, ODT, RTF, EPUB, JSON, and XLSX; XLSX requires code execution and file creation to be enabled. For images, Claude lists JPEG, PNG, GIF, and WebP. Non-PDF documents are generally handled through text extraction, so embedded images are not necessarily interpreted as visual content.
Gemini: 10 files per prompt, with separate rules for video, audio, and code
Gemini's published general rule is up to 10 files in the same prompt, subject to availability. For file size, each video can be up to 2 GB, while other supported file types can be up to 100 MB. This makes Gemini look more restrictive for large documents than ChatGPT and Claude, but much more explicit for media.
Google also applies duration limits. The combined length of uploaded videos can be up to 5 minutes under basic limits and 1 hour with Google AI Pro or Ultra. Audio can total 10 minutes, or up to 3 hours on Pro or Ultra. A 1.5 GB video can therefore still fail because it exceeds the allowed duration even though it is under the 2 GB file-size ceiling.
There is a useful exception for development workflows: one code folder or GitHub repository can be added to a chat with up to 5,000 files and a maximum size of 100 MB. ZIP files can be up to 100 MB and contain up to 10 files, but they cannot include audio or video.
Gems: Google does not publish a simple “total per Gem” figure
The Gems documentation allows knowledge files to be added from a device or Google Drive and points users to the general supported-file and upload-limit rules. The important point is not to turn the 10 files per prompt rule into an assumed “10 files maximum per Gem”: the dedicated Gems page checked for this article does not explicitly state that total cap.
Gemini also has rolling usage limits and an internal storage limit for Gemini Apps activity. The help page describes “you've reached your limit for chats with files” and “delete data to upload file” errors, but it does not publish a universal number of gigabytes for that storage on the page checked. In this case, the accurate answer is to acknowledge that the total is not documented there rather than invent a quota.
Which tool best accepts your real file set?
- Up to 20 documents in one round: ChatGPT and Claude have an advantage over Gemini's general 10-file-per-prompt rule.
- One very large document in MB: ChatGPT reaches 512 MB and Claude 500 MB in chat, but both apply additional content limits; Claude also caps PDF page counts.
- Many files as persistent knowledge: ChatGPT has explicit per-project counters; Claude describes the file count as unlimited but bounded by total knowledge capacity; Gemini supports knowledge in Gems but does not expose a similarly clear total-per-Gem number on the page checked.
- Audio and video: Gemini provides the clearest published size and duration rules. ChatGPT supports video attachments in compatible flows, but its own help warns that analysis may be incomplete and that video handling is separate from still-image inputs. Claude's standard upload documentation focuses mainly on documents and images.
- A code repository with thousands of files: Gemini has a specific rule for one code folder/GitHub repository of up to 5,000 files and 100 MB, avoiding the need to treat thousands of source files as thousands of separate attachments.
- Spreadsheets: ChatGPT caps CSV/spreadsheet files at about 50 MB; Claude supports CSV and XLSX, but XLSX depends on code execution being enabled; Gemini accepts spreadsheets within its general supported-file rules.
Why does an upload fail even when it is “within the limit”?
- You checked the wrong limit. The file fits in MB but exceeds tokens, pages, duration, or files per upload.
- Chat and project rules differ. In Claude, for example, 500 MB in chat and 30 MB per project file are separate rules.
- The format is not supported in that path. A service may accept a type in chat but not in a persistent knowledge base or specific modality.
- You hit a rolling quota. OpenAI and Google document usage limits that reset over time; in ChatGPT, even failed attempts can count toward the upload rate.
- You hit storage. ChatGPT and Gemini treat file/activity storage separately from some upload limits. For Gemini, the total numeric storage cap is not published on the help page checked.
- Your plan or workspace changes the rule. Projects, audio/video duration, file counts, and integrations can depend on plan level or administrator settings.
- The file uploads, but analysis is partial. A successful upload does not guarantee that every page, embedded image, audio segment, or distributed detail will be processed with equal depth.
Checklist before switching tools
Count the files, identify the largest one in MB, list the formats, and for very long documents estimate pages or tokens. For audio and video, check duration too. Then decide whether the set is for one-time use in a chat or must become persistent knowledge. Only after that should you compare against the relevant limit column.
For mixed file sets, the most robust test is to try the largest file, the least common format, and the maximum number you plan to attach at once. That quickly reveals whether the bottleneck is size, type, count, context, or storage — and prevents choosing a tool based only on the biggest number in its documentation.
Conclusion: “how many files fit” depends on the bottleneck
As of August 31, 2026, ChatGPT and Claude reach 20 attachments in one chat round, while Gemini publishes 10 per prompt. ChatGPT and Claude allow much larger individual files for common documents, but add token, page, project, and storage constraints. Gemini is more restrictive on general document size, yet has explicit rules for audio, video, ZIP files, and code repositories.
If your decision depends on a specific file set, do not compare only “20 versus 10” or “512 MB versus 500 MB.” Compare count + largest file + format + duration/pages/tokens + persistence + usage quota. That combination determines whether the upload actually succeeds.
