Tryit Editor v1.8

Source Code:
<!DOCTYPE html> <html> <head> <style> span.highlight { background-color:yellow; } </style> </head> <body> <p> <span class="highlight">This is a text.</span> This is a text. This is a text. This is a text. This is a text. This is a text. This is a text. This is a text. This is a text. <span class="highlight">This is a text.</span> </p> </body> </html>
Result:
W3Schools.com - Try it yourself