Our paper introduces and assesses the Levumi platform’s web-based assessment of reading fluency. One challenges of inclusive education is meeting the needs of the learners with special education needs (SEN). Children with SEN and other risk factors face an increased risk of failing in schools and manifesting academic and social problems over the time. Web-based curriculum-based measurement (CBM) can provide an effective tool to track progress of learners and limit such risks. In particular, it can ease the challenges of test administration in inclusive classrooms through automation and providing multiple difficulty levels without the need of different paper-forms. Furthermore, Levumi can help educators track children and thus provide support for learners. Levumi takes advantage of the strengths of web-based CBM to assess reading fluency in primary school students. We confirmed the reading fluency test’s test-retest reliability (n = 334), its ability to measure learning over time in individual learners with SEN (n = 8, across 14 MPs), and its applicability to learners with SEN (n = 300, including n = 46 with SEN). We evaluate Levumi’s overall usefulness in assessing different types of learners, and discuss its contributions to CBM research.