One of the things you need to score well in IELTS is a well developed vocabulary. If you want a high band score in IELTS you need to be able to show the IELTS examiner that your vocabulary is more than just basic or intermediate level.
Improving your IELTS vocabulary takes time and practice. You need to get experience seeing vocabulary words in context and also develop your ability to guess certain words that you don't know - by using the surrounding vocabulary words to give you an idea of the possible meaning.
This is a great resource for boosting your IELTS vocabulary, especially for candidates doing the Academic IELTS. It's full of topical and interesting articles for IELTS reading practice, which will challenge your reading comprehension skills and help develop your IELTS vocabulary. You can also listen to all the articles, which will improve your listening comprehension skills for IELTS too.