<input onkeydown="return /[a-z]/i.test(event.key)" > //allow WHITE space as well <input onkeydown="return /[a-z\s]/i.test(event.key)" >
Preview:
downloadDownload PNG
downloadDownload JPEG
downloadDownload SVG
Tip: You can change the style, width & colours of the snippet with the inspect tool before clicking Download!
Click to optimize width for Twitter