Here's the Firefox Developer Tools output for Net, on a page reload immediately after the original page load (which seems to cut down drastically on requests due to caching which makes it easier for me to copy/paste the only 3 lines)
[02:27:36.182] GET https://medium.com/ [HTTP/1.1 200 OK 538ms]
[02:27:40.346] GET https://use.typekit.net/c/ec2d65/ff-tisa-web-pro:i4:i7:n4:n7,freight-sans-pro:n5:n7.Vdl:K:2,Vdq:K:2,Vdk:K:2,Vdp:K:2,TJD:K:2,TJJ:K:2/d?3bb2a6e53c9684ffdc9a98f7195b2a621af3706c43fd27fb1c2ac857895f9c1aa6e0a150c34a58a8cc268e093140e6a1c68d195f68c7ab5421d37c9f8037314acfccd341c5549953c3a5458d2153cf8598355c0169dde8a5e929e0abaef018efc3172b52ac4ce90d2e52930933d272c500a79829545c0b6ce81c15e104d6e141cf6a16eac595caa6382b0e1d176e5adc9bf2c5223ee5a452e892ca4cc2ddd59f9a101d5108046fb341684043b4aaa0808e0352746b2dd67d4d08453cb5a64ec80e36d899fbceb49c43ffc6ad03f5d251dc23736866 [HTTP/1.1 403 Forbidden 12ms]
[02:27:44.154] POST https://medium.com/_/stat/ [HTTP/1.1 200 OK 41ms]
Thanks, this is useful. It's weird you are getting a 403 on the typekit request. It looks like the font-loader probably just times out. Do you happen to have any extensions that might strip referrer
Bingo. That's the problem. Sorry, I figured starting Firefox in safe mode reverted my custom config. I had disabled referrer via about:config's network.http.sendrefererheader. Changing that value back to '2' (send referrer headers always) eliminates the problem. I guess only amongst HN readers can you count on people not sending this header. Anyhow, if TypeKit could not require this, that would be great. Thanks for looking into this, even though it might only help .001% of users.
