Grok file upload limits in 2026: 150 MB files, ~100 web attachments, formats, PDF, audio, video, and API limits

Grok supports much broader file handling in 2026 than a single universal upload limit suggests. On the consumer web app, current xAI documentation says users can attach up to roughly 100 files in one message, while Android supports up to 20; most documents, images, code files, and audio files can be as large as 150 MB each.

The developer API follows different rules. The xAI Files API allows files up to 512 MB, while direct image input has a separate 20 MiB limit and officially supports JPG/JPEG and PNG. These numbers should not be mixed with the consumer-chat limits because they describe different ingestion paths.

For PDFs, spreadsheets, presentations, source code, images, audio, and video, the usable limit is therefore determined by the product surface, file type, and how Grok processes the attachment rather than by one account-wide number.

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Surface	Current limit	Typical supported inputs	Practical note
Grok web	Up to ~100 files per message; most files up to 150 MB each	PDF, DOCX, TXT, CSV, XLSX, PPTX, JSON, code, images, audio, video	Broadest consumer upload support
Grok Android	Up to 20 files per message; most files up to 150 MB each	Common documents, data, code, images, audio and video	Platform support can vary
Grok iOS	Multiple files supported; most files up to 150 MB each	Common documents, images, audio and video	Exact attachment count can vary
xAI Files API	512 MB per file	PDF and many text-based formats	Agentic file search; separate from consumer chat limits
xAI image input	20 MiB per image	JPG/JPEG, PNG	API image-specific limit

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CONSUMER CHAT LIMITS — WEB, ANDROID, AND IOS

On grok.com, xAI currently documents support for up to approximately 100 files in a single message. Android supports up to 20 files per message, while iOS supports multiple files without the same published numeric cap. Platform behavior can still vary as clients are updated.

For most files — including documents, images, code, and audio — the current consumer limit is up to 150 MB per file. Very long documents may be summarized or processed in sections rather than loaded verbatim into a single model context.

A 120 MB PDF can therefore be uploadable on the consumer web app while still being too large or unsuitable for a different Grok surface. File size, attachment count, parsing support, and model context are separate constraints.

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SUPPORTED FORMATS — DOCUMENTS, DATA, CODE, MEDIA

Current Grok consumer documentation lists broad document and data support: PDF, DOCX, TXT, CSV, XLSX, PPTX, HTML, XML, JSON, Markdown, LaTeX, ODT, and RTF, together with common source-code formats such as Python, C++, Java, HTML, and CSS.

Image support includes JPEG/JPG, PNG, WebP, HEIC, and BMP. GIF and SVG support can vary by platform. Audio support includes MP3, WAV, M4A, OGG, FLAC, and AAC, while MP4 and MOV are listed for video.

Mixed uploads are supported, so a single request can combine a PDF, spreadsheet, image, text file, and code. This is useful for reconciliation, document comparison, extraction, and cross-file analysis.

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PDFS AND LARGE DOCUMENTS — WHAT THE SIZE LIMIT DOES NOT GUARANTEE

An upload succeeding does not mean every page, embedded image, table, or appendix will receive equal attention. For PDFs above roughly 100 pages, xAI recommends referring to specific page numbers when asking detailed questions because Grok may focus on extracted text and key visuals.

Embedded images inside non-PDF documents may not always be processed visually. Encrypted, password-protected, damaged, or unusual files can also fail even when their extension is nominally supported.

For extraction-heavy work, a better workflow is to ask for a structured result — for example a CSV or JSON table — and then validate high-value fields such as totals, dates, contractual clauses, or page references.

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XAI FILES API — THE 512 MB DEVELOPER LIMIT

The xAI Files API is a separate developer workflow designed for attaching documents to agentic model requests. Its current documented maximum is 512 MB per file, substantially above the 150 MB consumer-chat figure.

When a developer attaches a file to a compatible agentic model, xAI automatically enables attachment search so Grok can search and reason over the document. File context can persist across turns, which makes the API suitable for multi-step document analysis.

The Files API supports PDF, TXT, Markdown, code files, CSV, JSON, and many other text-oriented formats. It does not support batch mode for these agentic attachment-search requests.

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IMAGE INPUT THROUGH THE API — A DIFFERENT LIMIT AGAIN

Direct image understanding through the xAI API uses a separate rule: maximum image size is 20 MiB, with JPG/JPEG and PNG officially supported. This is not the same as the broader 150 MB consumer upload ceiling.

The distinction is operationally important. A large image file may upload through a consumer surface but exceed the direct API image limit, while a large text-oriented document can fit comfortably inside the 512 MB Files API ceiling.

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GROK BOT — SIX DESKTOP ATTACHMENTS AND DIFFERENT MEDIA CAPS

Grok Bot, xAI's persistent AI-teammate product, has its own attachment rules. Its desktop composer currently accepts up to six attachments at once; documents, images, and audio can be up to 25 MB each, while videos can be up to 200 MB.

Those Grok Bot figures should not be used as limits for ordinary grok.com chats or the xAI Files API. xAI operates several file-processing surfaces with different resource budgets and workflows.

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WHY AN UPLOAD CAN FAIL — SIZE IS ONLY ONE CAUSE

A file can fail because its format is unsupported on that platform, because the upload did not finish, because the document is encrypted or corrupted, or because a media type has inconsistent support between web and mobile clients.

If a file type fails, converting it to PDF, CSV, plain text, or a standard image format is usually the most reliable fallback. For extremely large documents, splitting the file into logical sections can also improve both upload reliability and answer quality.

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DATA STUDIOS REFERENCE — WHICH LIMIT SHOULD YOU USE?

Use 150 MB as the practical current ceiling for most files in ordinary Grok consumer chats, with roughly 100 attachments on web and 20 on Android. Use 512 MB when building through the xAI Files API. Use 20 MiB for direct API image input, and use the separate 25 MB/200 MB rules only for Grok Bot.

The safest implementation rule is to validate against the exact product surface rather than storing one global Grok file-size constant. A workflow that moves between grok.com, mobile apps, Grok Bot, and the developer API can legitimately encounter four different limits.

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