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Preview of Cross-Origin Storage

Cross-Origin Storage by Thomas Steiner

Implements the proposed Cross-Origin Storage API, letting sites share files with your consent for a faster and more efficient web.

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Screenshots
Cross-Origin Storage popup window with the "View by Origin" section showing resources shared across origins (dark mode).Cross-Origin Storage popup window with the "View by Origin" section showing resources shared across origins (light mode).
About this extension
Implements the proposed Cross-Origin Storage API, letting sites share files with your consent for a faster and more efficient web.

Modern web applications often rely on very large files. By default, a web browser downloads a separate copy of these files for each website that uses them. This process can lead to slower load times, increased data consumption, and the use of significant local disk space for storing duplicate copies.

This extension creates a shared storage system within the browser, based on a proposed new Web standard. When a website needs a large, common file (like an AI model), it can, with your permission, check if that file has already been downloaded and stored by another website. If an identical copy is found, the website can use the local file instead of downloading it again.

Key Features & Benefits:

• Faster Load Times: Websites can load more quickly by using large files that are already available on your device, bypassing the need for a new download.

• Reduced Data Usage: By eliminating redundant downloads of the same files across different websites, the extension helps conserve your internet data.

• Efficient Disk Space: Only one copy of a shared file is stored locally, preventing the accumulation of duplicate files and saving space on your computer's storage.

• User-Controlled Permissions: Websites cannot access the shared storage without your explicit approval. The extension will ask for your permission before a site can check for or use a shared file.

• File Integrity: The system uses cryptographic hashes to verify that the contents of a shared file are exactly what the website expects and have not been modified, ensuring security.

• Lower Energy Consumption: Reducing the amount of data transferred over the network contributes to lower overall energy use.

(Source code on GitHub: https://github.com/web-ai-community/cross-origin-storage-extension.)
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Permissions and data

Required permissions:

  • Access browser tabs
  • Access your data for all websites

Optional permissions:

  • Access your data for raw.githubusercontent.com

Data collection:

  • The developer says this extension doesn't require data collection.
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More information
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Version
0.1.19
Size
96.68 KB
Last updated
a day ago (Jul 6, 2026)
Related Categories
  • Web Development
License
Apache License 2.0
Version History
  • See all versions
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