Category Archives: browsers

The Pitfalls of EventSource over HTTP/1.1

While there are many different ways for servers to stream data to clients, the Server-sent Events / EventSource Interface is one of the simplest. Your code simply creates an EventSource and then subscribes to its onmessage callback: Implementing the server side is almost as simple: your handler just prefaces each piece of data it wantsContinue reading “The Pitfalls of EventSource over HTTP/1.1”

AppOrWeb-to-WebApp Communication: Custom Scheme Handlers

I’ve previously written about Web-to-App communication via Application Protocols. App Protocols allow web content to invoke a native application outside of the browser. WebApp advocates (like me!) want to continue to close the native/browser gaps that prevent web applications from becoming full-fledged replacements for native apps. To that end, I’ve recently spent some time lookingContinue reading “AppOrWeb-to-WebApp Communication: Custom Scheme Handlers”

Thoughts on DNS-over-HTTPS

Updated November 30, 2020 with new information about DoH in Edge, ECH, and HTTPSSVC records, and January 25, 2021 with a few remarks about Edge’s implementation. Type https://example.com in your web browser’s address bar and hit enter. What happens? Before connecting to the example.com server, your browser must convert “example.com” to the network address atContinue reading “Thoughts on DNS-over-HTTPS”

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”

Restrictions on File Urls

Last Update: October 1, 2025 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 or PDF, nothing visibly happens. If you open the Developer Tools console on the webpage,Continue reading “Restrictions on File Urls”

Same-Site Cookies By Default

The Chrome team is embarking on a clever and bold plan to change the recipe for cookies. It’s one of the most consequential changes to the web platform in almost a decade, but with any luck, users won’t notice anything has changed. But if you’re a web developer, you should start testing your sites andContinue reading “Same-Site Cookies By Default”

Aw, snap! What if Every Tab Crashes?

Update: I wrote a more comprehensive post about troubleshooting browser crashes. For a small number of users of Chromium-based browsers (including Chrome and the new Microsoft Edge) on Windows 10, after updating to 78.0.3875.0, every new tab crashes immediately when the browser starts. Impacted users can open as many new tabs as they like, butContinue reading “Aw, snap! What if Every Tab Crashes?”

Web-to-App Communication: DirectInvoke

Note: This post is part of a series about Web-to-App Communication techniques. Background Typically, if you want your website to send a document to a client application, you simply send the file as a download. Your server indicates that a file should be treated as a download in one of a few simple ways: Specifying aContinue reading “Web-to-App Communication: DirectInvoke”

Livin’ on the Edge: Root Causing Regressions

As we’ve been working to replatform the new Microsoft Edge browser atop Chromium, one interesting outcome has been early exposure to a lot more bugs in Chromium. Rapidly root-causing these regressions (bugs in scenarios that used to work correctly) has been a high-priority activity to help ensure Edge users have a good experience with ourContinue reading “Livin’ on the Edge: Root Causing Regressions”