oninput="this.value = this.value.replace(/[^A-Za-z0-9-,.;'&/.() ]|^ /g,'')"

ReCaptcha 
ReCaptcha v2 for Contact Form 7

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