Vocabulary Study Online By Level (VSOBL) is an all-in-one tool to prepare English exam vocabulary (US$2/Month). It has built-in vocabularies: 6000 IELTS words, 6000 TOEFL words, 5000 GRE words, and 3000 SAT words. You can load them by level with one click.
SAT essay vocabulary consists of 500 moderately difficult words; many high school students may learn them somehow but cannot use them confidently. This SAT word list includes examples, contexts, and interactive spelling exercises to build a solid essay vocabulary and sharpen writing skills.
If an essay is only done in plain or simple words in SAT writing, the chance to shoot a high score is relatively low. As a general rule, better vocabulary rewards a higher score. Unlike big-size reading vocabulary, writing vocabulary relies on your choice. You can prepare a set of words, then just use them in the right place, in the right way, and with the right spelling.
Most students can study or review the 500 SAT essay vocabulary in 2 weeks; some can even finish in 1 week. Nevertheless, in a real writing test, several hard words are enough; you should avoid using too many difficult words in a short essay. For example, if you have 5-7 uncommon but proper words in your essay, it will definitely impress readers.
If your time is tight and you feel the vocabulary big or hard, you may shrink the list to 200-300 words by excluding some relatively rare words. Only a doable task can bring your future writing with both confidence and skill.