Claude errors if the image dimensions exceed 8000 pixels

[sebastienkothe]

Problem

When using take_screenshot on large viewports (e.g., testing responsive design on wide monitors or using fullPage: true on long pages), the tool fails with:

API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.7.content.2.image.source.base64.data: At least one of the image dimensions exceed max allowed size: 8000 pixels"}}

This happens frequently when testing responsive layouts, making the tool unusable for this common use case.

Expected behavior

Screenshots should be automatically resized to fit within Claude API limits (max 8000px per dimension) before being sent, preserving aspect ratio.

Reproduction

1. Open a page in a browser with a large viewport or long scrollable content
2. Call take_screenshot (especially with fullPage: true)
3. Tool fails with the above error

Suggested fix

Resize images before base64 encoding when any dimension exceeds 8000px, preserving aspect ratio. This is a common pattern in similar tools.

Environment

• MCP: chrome-devtools-mcp (latest via npx)
• Client: Claude Code
• OS: macOS

[OrKoN]

The MCP spec does not place limits on the image as far as I know. Do you know why 8000px is chosen? The existing workaround would be to save large images to file by passing the filePath parameter or calling page_resize beforehand.

[OrKoN]

Related Claude issue anthropics/claude-code#2939

[sebastienkothe]

The 8000px limit comes from Claude API's image constraints.

From the official Anthropic documentation:

If you submit an image larger than 8000x8000 px, it will be rejected. If you submit more than 20 images in one API request, this limit is 2000x2000 px.

Context	Max size per image
1-20 images	8000×8000 px
21-100 images	2000×2000 px

This explains both error messages seen in related issues (8000px vs 2000px depending on context).

Thanks for the workaround suggestions (filePath and page_resize). An automatic resize before sending to the API would still be a nice quality-of-life improvement to avoid these errors entirely.

[simplylizz]

I’ve been experiencing the same issue for quite some time, and it’s pretty annoying because it corrupts the Claude Code session.

Ideally, this should be fixed in Claude Code itself, but this bug has existed for a long time and is still present. So maybe it’s worth introducing some configurable parameters on the MCP side: one option could be automatic resizing if any side exceeds X pixels; another could be to fail the call with a clear error message stating that the screenshot exceeds specified size limit. This way, we would be able to set different settings and limits for different API providers or agentic coding tools.

[sitefinitysteve]

● chrome-devtools - take_screenshot (MCP)
⎿ # take_screenshot response
Took a screenshot of the current page's viewport.
⎿ [Image]
⎿ API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.57.content.1.image.source.base64.data: At least one of the image dimensions exceed max allowed size for many-image requests: 2000
pixels"},"request_id":"req_011CXvuVWi58eazvVLm8123w"}

Would be just nice to handle on the MCP screenshot tool, even if it's a resize or something. Sucks to just have an entire chat session get messed up

[OrKoN]

Please also post this on anthropics/claude-code#2939 We will see if we can have a work around here but if Claude Code fixes this, it would be ideal.

[sebastienkothe]

Thanks @OrKoN for the pointer! I'll cross-post on anthropics/claude-code#2939 with context about the MCP screenshot side of the problem.

Really appreciate you linking the issues together and being open to a workaround on the MCP side as well.

[MussaCharles]

In case anyone missed it. I built a workaround that auto-resizes oversized images before they reach the API. It's completely resolved this issue with chrome-devtools-mcp and most screenshot based tools like Playwright for me. Works as a Claude Code hook or plugin:

• https://github.com/MussaCharles/claude-code-image-sanitizer

[natorion]

This has to be fixed on the Claude side AFAIK. Limits are dependend on the MCP client and how it handles the images. Limits will also change when models change. It's not feasible for us to maintain this.

filePath is exactly the solution that should be used in such cases. I wonder, does Claude not try it again with that particular parameter enabled, after it fails?