There are several free online journals available that do not require subscriptions, particularly in the fields of physical science and mathematics. Users can register for free access to the Institute of Physics (IoP) journals, which allows viewing all papers within the first 30 days of publication. The New Journal of Physics is also consistently available for free. The American Physical Society (APS) offers two free journals: Physical Review Special Topics - Accelerator and Beams and Physical Review Special Topics - Physics Education Research. Additionally, platforms like arXiv provide free access to a wide range of preprints and research articles. Other resources mentioned include Living Reviews in Relativity and the Philosophy of Science Archive, which also offer free content.