A guitar tuner is an invaluable tool for any guitarist, especially beginner guitarists who may not yet have the experience to know if their strings are in tune. A guitar tuner works by using the microphone on your device to detect the tone of a string and then matching it against a reference frequency for that particular string. Then a needle or some other visual indicator tells you when your guitar string has reached the correct pitch.

There are lots of different tuner apps available for your device, but it's important to think about what features you want in a tuning app before downloading one. For example, are you looking for an app that's easy to use or do you need something that's more detailed and accurate? Also, think about whether you need your online tuner to be portable or if it's just for home use.

The most popular guitar tuner Afinador online apps tend to be free, but there are some great ones that cost money too. For example, the excellent Guitar Tuna has lots of features that make it one of the best guitar tuner apps for advanced players, but it's not cheap.

Another free option is the GuitarPro online guitar tuner which is easy to use and has a nice big display. It's also fully chromatic and can tune acoustic guitars, electric guitars, bass guitars, and ukuleles. To use the tuner, simply click on the red microphone icon and then give your device permission to access your microphone (you may need to change settings in your browser depending on your device).

For those looking for a more premium tuner app, CarlTune is an excellent choice. It's easy to use and has a great display, showing you the note that you're playing and how sharp or flat it is in Hz. It also shows you where the note would be on a piano stave, which is very helpful for those that are used to reading music notation. This app is fully chromatic and can tune up to two decimal places, and it can even tune outside of the standard 440Hz frequency.

Fender also have an online guitar tuner that's easy to use and fully chromatic. It's surprising that the online version doesn't include any learning facilities like the smartphone app, but it's still a great tuning tool.

The only downside of this tuner is that it requires mic access through your web browser, so if you're concerned about privacy then it's not the right choice for you.

Many people who play guitar or other instruments don't have access to apps stores on their devices, or they just prefer not to have another app taking up space on their device. In that case, an online tuner is the best option. These online guitar tuners work through your device's microphone and are completely free to use. However, beware of online guitar tuners that have a lot of advertising as they can become very distracting and can take you to websites that you don't want to be on.