"Just Tonight" received mostly positive reviews from critics. Robert Copsey of
Digital Spy gave it four out of five stars, saying, "A song about being stuck in a flagging relationship may not tread any new lyrical ground, but when it's backed by a chunky pop/rock melody, thrashing guitars and oh-so smoky vocals, the result is more gratifying than that first sip of blue
WKD round ya mate's". Fraser McAlpine of
BBC Radio 1's The Chart Blog gave the song four out of five stars, praising singer Momsen's vocals and describing the song as "a thoughtful, hurt sort of a song" that "plays straight—from the heart to the heart—and is all the better for it." OddOne of Unreality Shout rated the song four-and-a-half out of five stars, calling it "just brilliant—there's hooks, emotion, thought-provoking lyrics, all topped off with a monstrous chorus that brings plenty of teenaged angst to proceedings". In a less enthusiastic review, Rebecca Nicholson of
The Guardian felt that the song "sounds like
Evanescence doing a song for the sole reason of soundtracking an emotional scene on ''
Grey's Anatomy''". ==Live performances==