What is Time to First Byte (TTFB)?
Time to first byte (TTFB) measures the time between a browser requesting a webpage and the server sending the first byte of information of the requested webpage.
Time to first byte is one of the metrics used for measuring page speed. In this case, it is excellent for identifying servers that are too slow to respond to requests.
While the time to first byte is not a Core Web Vitals metric, Google recommends keeping it below 0.8 seconds. You can measure your website’s TTFB using the PageSpeed Insights tool.