Microsoft’s Three Browsers

It’s an interesting time. Microsoft now maintains three different web browsers: Internet Explorer 11 Microsoft Edge Legacy (Spartan, v18 and below) Chromium-based Microsoft Edge (v79+) If you’re using Internet Explorer 11, you should stop; sometimes, this is easier said than done. If you’re using Legacy Microsoft Edge, you should upgrade to the new Microsoft EdgeContinue reading “Microsoft’s Three Browsers”

Security Zones in Edge

Browsers As Decision Makers As a part of every page load, browsers have to make dozens, hundreds, or even thousands of decisions — should a particular API be available? Should a resource load be permitted? Should script be allowed to run? Should video be allowed to start playing automatically? Should cookies or credentials be sentContinue reading “Security Zones in Edge”

Retiring Internet Explorer

Prelude In late 2004, I was the Program Manager for Microsoft’s clipart website, delivering a million pieces of clipart to Microsoft Office customers every day. It was great fun. But there was a problem– our “Clip of the Day” feature, meant to spotlight a new and topical piece of clipart every day, wasn’t changing asContinue reading “Retiring Internet Explorer”

Disabling TLS/1.0 and TLS/1.1 in the new Edge Browser

UPDATE: Timelines in this post were updated in March 2020, October 2020 and April 2021 to reflect the best available information. HTTPS traffic is encrypted and protected from snooping and modification by an underlying protocol called Transport Layer Security (TLS). Disabling outdated versions of the TLS security protocol will help move the web forward towardContinue reading “Disabling TLS/1.0 and TLS/1.1 in the new Edge Browser”

bye: FTP Support Is Going Away

Support for the venerable FTP protocol is being removed from Chromium. Standardized in 1971, FTP is not a safe protocol for the modern internet. Its primary defect is lack of support for encryption (FTPS isn’t supported by any popular browsers), although poor support for authentication and other important features (download resumption, proxying) also have hamperedContinue reading “bye: FTP Support Is Going Away”

Improving Privacy by Limiting Referrers

Updated July 31, 2020 to reflect changes planned to ship in Chrome 85 and Edge 86. As your browser navigates from page to page, servers are informed of the URL from where you’ve come from using the Referer HTTP header1; the document.referrer DOM property reveals the same information to JavaScript. Similarly, as the browser downloads theContinue reading “Improving Privacy by Limiting Referrers”

Restrictions on File Urls

For security reasons, Microsoft Edge 76+ and Chrome impose a number of restrictions on file:// URLs, including forbidding navigation to file:// URLs from non-file:// URLs. If a browser user clicks on a file:// link on an https-delivered webpage, nothing visibly happens. If you open the Developer Tools console, you’ll see a note: “Not allowed to load local resource:Continue reading “Restrictions on File Urls”

Edge79+ vs. Edge18 (Edge Legacy) vs. Chrome vs. Internet Explorer

Note: I expect to update this post over time. Last update: Sept 27, 2021. Compatibility Deltas As our new Edge Insider builds roll out to the public, we’re starting to triage reports of compatibility issues where Edge79+ (the new Chromium-based Edge, aka Anaheim) behaves differently than the old Edge (Edge18, aka Spartan, aka Edge Legacy)Continue reading “Edge79+ vs. Edge18 (Edge Legacy) vs. Chrome vs. Internet Explorer”

Script-Generated Download Files

As we finish up the next release of Windows 10, my team is hard at work triaging incoming bugs. Here’s a pattern that has come up a few times this month: Bug: I click download in Edge Legacy: …but I end up on an error page: Womp womp. If you watch the network traffic, you’llContinue reading “Script-Generated Download Files”