TTSReader is a versatile text-to-speech reader with many languages and accents. You can listen to web pages, export audio files and even inject a single line of code into your website to make it speak. It's good for proofreading, accessibility and learning a language, with free and premium options.
Another serious option is Audioread, which uses very realistic voices for longer listening sessions. You can convert text from articles, PDFs and emails into an audio version. Audioread works on multiple operating systems and offers a private podcast RSS feed so you can listen to your own content in your favorite podcast apps or directly in the browser.
If you want more control, check out ReadSpeaker. This service offers a lot of voices and languages, along with options like simultaneous highlighting and translation. It's WCAG 2.2 compliant and can be integrated with content and learning management systems, so it's good for people with literacy or learning difficulties.
Last, Peech lets you convert text into audio immediately in more than 50 languages. It can handle lots of input formats, including web pages and PDFs, and you can customize speed and language. Peech is available for iOS, with an Android app in the works, so it's good for people who want to multitask, learn or create content.