Currently, there is still not too much fierce competition in TTS. Among all the ones that I tried, Read Aloud is the best. talkie is a half finished, product, speed adjustment is in the "coming soon" premium version, which I suppose is not free. Chirpy is a DOA. "Text to speech that brings productivity" is a godzilla for such an easy task. Firefox's own reader mode TTS is also a flop. In Japanese text, it skipped the dates and and was sluggish on words. Sentence sounds like a bag of words.

Read Aloud allows me to choose voices, such as the superior Google Japanese female voice that just rocks! She read through dates and English words in Japanese text like a local. "Macron" sounds more recognizable than any other TTS. Currently the go to TTS in my Firefox.

Best TTS extension ever used

It's Fantastic. Use full addon. It support Sinhala language also.

Awesome add on! Only issue is that I cannot sign in to access Premium voices.

It's hands down the best TTS extension that I ever used. Too bad it doesn't work in private browsing mode. Hopefully it can be fixed.

I've tried more than 5 different TTS addons, but none of them functioned as well as this one. Both English and Turkish is being read alout quite well and without any hussles. The initiation and ending of the reading is very intiuitive and works just fine.
I definitely suggest trying out this addon.

Esta muy buena la app, se lee rapido y con muchas opciones

This is a excellent add-on. I am Chinese and I can read English but I read very slow. With this add-on, I can read faster and can understand some of the words I do not know. The add-on also give us a lot of voice choices including man and woman voice.

The TTS (multi-language tts) worked well enough but stopped reading PDFs as FF was updated and the developer perhaps gave up. This add-on reads my PDFs beautifully and all the controls work perfectly. Thank you. Thank you.

Great usability. Amazon voice "Kimberly" sounds the best to me. Very listenable.

Yeah i like how it highlights. This Text to speech FF addon is awesome!!! Yay!

This is an awesome addon and is free/libre software