STEP Bible (Scripture Tools for Every Person) started in 2011 as a project of Tyndale House, and became an independent charity in 2020. It provides extremely helpful tools for studying the Bible, including not only numerous English translations, but also many ancient language versions. You can hover over a word in an English translation to see the underlying original word, and when you click on a word, the text highlights other occurrences of it in the chapter. The best thing is a panel on the right which opens to show the underlying Hebrew or Greek word, the number of times it appears (you can click to see all the occurrences), the possible meanings, and related words. You can also display the English and the Hebrew or Greek together so that you can see the word order. STEPBible is by far the best tool there is for digging into the original words without learning Hebrew or Greek first.
There is an excellent guide to using STEP Bible, with video tutorials and comprehensive instructions.
Lumina / NET Bible
The NET Bible (New English Translation) from Bible.org is an open-source translation that has over 60000 translators’ and study notes. These enable you to see what decisions have been made about alternative translations, and explain difficult phrases. These notes are extremely helpful.
The Net Bible online (also called Lumina) first shows you the NET text on the left with the translation notes on the right, but you can also display original language versions side by side with the English. As with STEP Bible, you can click on a word to highlight all the occurrences in both the English and Hebrew or Greek, and a small box displays possible meanings. You also get a popup allowing you to quickly see parallel renderings in the English translations available in the Lumina suite, and to do a word search. There are very good video tutorials available.
BibleGateway has the most comprehensive range of translations, not only in English but many other languages. Hebrew and Greek are also available, which you can show side-by-side with modern translations, but to be able to interact with a word you need a paid subscription. This also gives you access to commentaries, dictionaries, maps and more.