# Page edits return 400 when a page is too large to load

By Steven Van · 2026-10-02

The change covers the markdown API and Notion MCP, with edits restricted to content outside unknown tags.

Developers editing large pages through [Notion](<https://creatorstoolbox.com/tools/notion>)'s markdown API or notion-update-page MCP tool now receive HTTP 400 validation\_error instead of HTTP 500 internal\_server\_error when an edit touches content that could not be loaded.

## When the error occurs

The change applies when a page is too large to load in full, at about 20,000 records, most of them blocks. An edit fails if it targets an unloaded block or would remove unloaded content. Retrying the same request produces the same failure.

## Editing around unloaded content

When retrieving a page as markdown, unloaded content appears as unknown tags. Edits should target only content outside those tags. The error response identifies the limit through additional\_data.limit\_kind, set to page\_record\_count, and additional\_data.limit, which holds the limit. The [markdown update documentation](<https://developers.notion.com/reference/update-page-markdown>) is linked from the October 2 release note.

![Notion](<https://www.google.com/s2/favicons?domain=notion.so&sz=128>)

Notion

All-in-one workspace for notes, docs, projects, and wikis — with AI built in for writing, summarizing, and organizing.

[View Notion →](<https://creatorstoolbox.com/tools/notion>)

Sources

[Original source](<https://developers.notion.com/page/changelog#october-2-2026>)

[Read Page edits return 400 when a page is too large to load on Creators Toolbox](<https://creatorstoolbox.com/blog/notion-page-edits-return-400-when-a-page-is-too-large-to-load>)

---
Canonical source: https://creatorstoolbox.com/blog/notion-page-edits-return-400-when-a-page-is-too-large-to-load