HTML Preview
Write HTML and instantly preview the rendered output in a sandboxed frame.
Preview
Frequently Asked Questions
Is the preview truly live, or do I have to click Run every time?
Auto-run is enabled by default, and the iframe refreshes 500 ms after you stop typing. If you turn Auto-run off, then Run becomes the manual refresh control.
Will my JavaScript run inside the preview?
Yes, the iframe uses `sandbox="allow-scripts allow-same-origin"`, so scripts can execute inside the preview pane. It is still an iframe sandbox rather than a normal full browser tab.
Why don't changes appear instantly on every keystroke?
The tool debounces updates by half a second to avoid reloading the iframe on every single input event. That delay is intentional.
Can I resize the editor and preview panes?
Yes. On desktop, drag the divider or use the divider's arrow-key support; the split is clamped between 25% and 75%.
Why is there no draggable splitter on my phone?
Below the mobile breakpoint, the layout collapses to one column and the divider is hidden. That's why the resizable split view only appears on wider screens.