https://hongjae.pages.dev/en/tags/browser/ Recent content in Browser on Jaehyun's Blog https://pub-8eb6fdee382f4b0390e652016dc5f15a.r2.dev/og-image.jpg https://pub-8eb6fdee382f4b0390e652016dc5f15a.r2.dev/og-image.jpg Hugo -- 0.118.2 en Thu, 02 Jul 2026 00:00:00 +0000 https://hongjae.pages.dev/en/posts/260702-stable-http-request-on-page-exit/ Thu, 02 Jul 2026 00:00:00 +0000 https://hongjae.pages.dev/en/posts/260702-stable-http-request-on-page-exit/ Navigator.sendBeacon() is designed to send data when a page is unloaded. It guarantees delivery even if the page is closed. Basic usage: navigator.sendBeacon('/log', JSON.stringify({ some: 'data' })); The API does not allow custom headers. To send JSON with the proper Content-Type, use a Blob. <a href="/some-other-page" id="link">Go to Page</a> <script> document.getElementById('link').addEventListener('click', (e) => { const blob = new Blob([JSON.stringify({ some: 'data' })], { type: 'application/json; charset=UTF-8' }); navigator.sendBeacon('/log', blob); }); </script> Compared to fetch with keepalive, sendBeacon uses low priority, so it does not interfere with critical page actions.