Compare Chrome Extension Versions

How to compare Chrome extension versions

Short answer

To compare Chrome extension versions, download both packages, inspect each manifest and code, then diff permissions, host patterns, content-script matches, external domains and code findings. Focus on capabilities that grew between versions, such as new cookies access or broad host patterns, and check whether the release notes explain them. A static diff shows change, not intent.

Drop an extension package hereor choose a file from your deviceChoose a fileSupported: CRX, XPI, ZIP, manifest.json. Maximum size: 25 MB.

Processed locallyCode is never executed

Your file stays in this browser. Parsing happens in a Web Worker; the extension code is read, never executed.

What the scan checks

Permissions, host access, content scripts, background scripts, CSP, externally_connectable, web-accessible resources, JavaScript patterns, referenced domains and risk categories.

MV3MV2CRXXPIZIPJSON

Static analysis shows references and patterns. It cannot prove that network activity happened or that an extension is malicious.

Compare two versions

See permission, domain and finding changes between two packages.

Compare

Collect both packages

Keep the version you already reviewed and obtain the update. If the extension is installed, use the browser's extension page to find the version number, then download the matching CRX or unpacked package. For Firefox, download the XPI. Store both files together so the comparison is reproducible.

A version diff is only meaningful when the two packages are the actual builds you are comparing. Mixing a store build with a developer ZIP can create false differences in minification, build flags or bundled dependencies.

Record the version number and release date for both packages
Prefer the same distribution channel for both builds
Keep the original files until the review is complete

Diff the manifest first

The manifest is the fastest place to spot a capability change. Compare permissions, optional_permissions, host_permissions and content_scripts.matches. A new all_urls pattern or a new cookies permission is more consequential than a renamed action popup.

Also check externally_connectable, web_accessible_resources and the content security policy. These fields control who can talk to the extension and what resources pages can reach.

Manifest fields to compare
Field	What a change can mean
permissions	New browser API access
host_permissions	Broader website access
content_scripts.matches	Code injected into more pages
externally_connectable	New web page communication
web_accessible_resources	More resources exposed to pages

Review code and domain changes

After the manifest, compare code findings and external domains. New remote script references, credential access, clipboard reads or raw IP endpoints deserve a closer look. A new analytics domain may be expected; an unexplained endpoint on a login page is harder to justify.

Static analysis can flag bundled library code that the publisher did not write. Read the surrounding file and line before treating a finding as evidence of intent.

Frequently asked questions

Can I compare Chrome extension versions without installing them?

Yes. Download both packages and inspect them statically. You can compare manifests, code findings and domains without loading either version in a browser profile.

What is the most important change in an extension update?

A new broad host permission or a new sensitive API permission is usually more important than a version bump. Check whether the release notes explain the feature that needs it.

Does a new domain in an update mean the extension is unsafe?

Not by itself. A new domain may support a new feature or a changed backend. Review the code context and the publisher's privacy policy before deciding.

Can a version diff detect a compromised update?

It can surface suspicious changes, but it cannot prove compromise. A compromised build may reuse existing permissions and domains, so runtime behavior and publisher communication still matter.

Last reviewed: November 1, 2026