Spellcheck support is within the browser in IE 10+, all versions of Edge, all versions of Firefox, Chrome 9+, Safari 5.1+ and Opera 11.5.

These browsers will automatically flag any unrecognised word; usually with a red underline. Right-clicking on an underlined word will bring up a menu of options. This lets you choose to correct the word or add it to your dictionary.

If you are unable to upgrade your browser, you may be able to install a browser add-on to provide spellcheck support. Check with your browser provider.

While browsers have spellcheck enabled by default, it is possible to turn it off. Check your settings as below: