Last updated: August 16, 2026
Preview Renderer for Drive is a Chrome extension that lets you view Markdown and HTML currently shown in Google Drive as readable static previews without downloading the files.
This page covers improvements made after the initial release and the changes included in each published version.
Release status
Version 1.5.4 (August 17, 2026; preparing for release)
Clarified why an oversized external image was blocked
When an external image exceeds the 1 MiB per-image limit, the display-restriction details now explain the reason as follows:
External images: N — Blocked because the 1 MiB per-image size limit was exceeded.
This update does not change the external-image size limit, host selection before loading, or Chrome’s additional access prompt. It also does not relax the extension permissions, sandbox, Content Security Policy, or conditions for retrieving external resources.
Version 1.5.3 (August 16, 2026; published)
Added image display levels
You can choose one of four levels for images and SVG in files from the Options page.
- Level 0: Do not display images
- Level 1: Display embedded PNG, JPEG, and WebP images that pass validation
- Level 2: Display Level 1 images and basic SVG (default)
- Level 3: Display Level 2 content plus gradients, markers, limited same-SVG references, and other compatible SVG features that pass validation
Validation checks apply at every level. Even at Level 3, scripts, event handlers, `foreignObject`, animation, external references, and images or SVG that exceed safety limits are blocked. Level 3 does not allow every SVG feature.
Improved display-restriction explanations
- Standardized display-restriction messages by replacing “removed” with “blocked.”
- Made it easier to review why an image or SVG was blocked in the display-restriction details.
- Added guidance to check the Options page when an SVG cannot be displayed at the current image display level.
- Emphasized, in red and bold text on the Options page, both the content that remains blocked at every image display level and the information that may be shared during an external connection.
Improved guidance for large files
If the extension cannot verify the complete file from the content displayed by Google Drive, it does not start the protected preview and keeps the standard Drive view available.
The limit for verifying the complete file is 262,143 bytes (just under 256 KiB). When the limit is exceeded, the extension does not display only part of the file as a preview. It explains the reason and asks you to use the standard Drive view.
How this relates to external images
Increasing the image display level does not automatically load external images. To load an external image, you must enable external images on the Options page, select the relevant host for the current preview, and respond to Chrome’s additional access prompt.
Google Fonts is controlled separately from the image display level.
A destination may receive your IP address, connection time, and the URL of the font or image being requested. Selected hosts, full URLs, and permission history are not stored as extension settings.
Restrictions that remain in place
This update does not relax the extension permissions, the sandbox used by the preview iframe, the Content Security Policy, or the conditions for retrieving external resources.
Version 1.5.2 (August 10, 2026; published)
Improved toolbar and preview startup resources
Revised how extension-owned resources are loaded to display the toolbar and preview in Google Drive.
This change does not expose display resources to pages outside Google Drive. The extension permissions, external connection destinations, sandbox, and Content Security Policy remain unchanged from version 1.5.1.
Version 1.5.1 (August 7, 2026; published initial release)
The initial public release included the following features:
- Static previews for Markdown and HTML currently shown in Google Drive
- Markdown headings, tables, task lists, code blocks, and other common formatting
- Details about scripts, external loading, and other content restricted during preview
- Switching between Preview, Simplified view, and the standard Drive view
- Read-only Source view
- Japanese and English interfaces
- Display settings such as theme, text size, and page width
- Explicit settings for Google Fonts and external images
- Icons for the Chrome toolbar and extension management page
Important notes
- Preview Renderer for Drive does not reproduce every behavior or layout from the original HTML.
- Scripts, iframes, forms, and other content that is not required for static viewing may be blocked or stopped depending on the content.
- If the file does not meet the preview conditions or the complete file cannot be verified, use the standard Drive view.
- Enabling external resources may connect to the selected destination. Select only destinations you trust.
- Preview Renderer for Drive is not provided, endorsed, or sponsored by Google LLC.