Udemy's appeal for ISTQB CTFL prep is the price — self-paced video courses, often taught by well-known independent instructors, covering testing fundamentals, test process, test techniques, and test management at a fraction of official training rates. Several Udemy ISTQB CTFL courses are genuinely excellent and widely recommended by past candidates.
The gap is the same one that shows up across any self-paced marketplace: a video course can't tell you specifically which of testing fundamentals, test process, test techniques, and test management you're actually weak in. You finish the course knowing you watched everything, not knowing whether you've retained enough to pass.
Edureify's Diagnostic maps your understanding across testing fundamentals, test process, test techniques, and test management on day one, and the Readiness Score keeps updating as you practice — so instead of a vague sense of completion, you get a specific, evolving answer.