v137 · security · storage

Blob Lifecycle Tracer

Create blob URLs in this page, attempt to access them from different simulated partition contexts, and watch each event traced on a timeline. Blob URL partitioning means a blob URL is only accessible from the partition (top-level site + frame origin) that created it.

Create & probe blobs

Current blob URL
None created yet.

Event trace

Events will appear here.

Partition model

This page's partition

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Blob URLs created here are owned by this partition. Only this partition can fetch or navigate to them.


fetch: ✓ allowed

Foreign partition (simulated)

top=attacker.example / frame=attacker.example

A different top-level site attempting to access a blob URL created in the owned partition.


fetch: ✗ blocked
Partition key = (top-level site, frame origin). A blob URL created in partition A cannot be fetched or navigated to by code in partition B, even if the blob URL is somehow leaked (e.g. via postMessage). This prevents cross-site blob-URL side-channel attacks without requiring per-URL access control lists.

see also