Clasa is a free AI essay grading and detection tool, mainly designed for teachers, schools, tutoring institutions, and students, to help quickly complete the grading and feedback of essays and assignments.
Main Uses
Clasa's core use is essay grading. Users can upload essays and add a rubric or grading instructions, and the AI will grade the essays according to these standards and provide structured feedback. It is officially positioned as a tool to "complete grading in minutes instead of hours," suitable for a variety of writing tasks such as daily assignments, AP Lang practice, and college application essays.
Main Capabilities
Grading by custom rubric: Users can upload their own rubrics, or quickly build a rubric in minutes, including the AP Lang essay rubric; they can also reuse previously saved rubrics to ensure every essay is graded by the same standard. If there is no rubric, specific grading instructions can also be entered directly, and the system will evaluate according to these instructions.
Detailed feedback and annotations: Every evaluated essay receives a score aligned with the rubric or instructions, as well as detailed, context-aware comments. The comments are readable, editable, and shareable, so students can clearly know what needs to be revised. Feedback covers aspects such as structure, clarity, argument, evidence, and grammar, rather than just surface-level error correction.
AI content detection: Clasa can show the proportion of a submission that may be AI-generated, displayed alongside the grading results. The detection analyzes sentence by sentence and can further drill down to the phrase level, using color-coded annotations to distinguish human-written, suspected AI-generated, and ambiguous passages. The system also provides an overall likelihood score and transparent reasoning, making it easier for teachers and students to have evidence-based communication.
Multilingual and multi-genre support: Clasa currently supports essay grading in 31 languages, including English, Spanish, Japanese, Arabic, and Hindi, and the official statement says more languages are still being added. Supported genres include argumentative essays, synthesis writing, rhetorical analysis, AP Lang argument essays, narratives, expository essays, compare-and-contrast essays, literary analysis, research papers, and general academic writing, among others.
How to Use
The usage process is roughly as follows: first paste or upload the essay into the system, then set the grading standards—you can upload a rubric, reuse a saved rubric, or directly enter instructions; then click grade, and the AI grading engine will read paragraph by paragraph, scoring structure, clarity, argument, grammar, and evidence according to the rubric standards. After grading is complete, users can view the score for each criterion and annotated feedback,Edit any comment and download the complete scoring report as a PDF to share.
Use cases
Clasa provides corresponding scenarios for different roles:
Students: Check essays against the rubric before submission, get item-by-item feedback, understand writing performance, and improve assignments.
Teachers and educators: Use AI to grade essays to save time while maintaining grading consistency; apply rubric-based scoring to the whole class and make specific, editable adjustments before feedback reaches students.
Schools, colleges, and universities: Manage essay grading at scale and maintain consistent assessment standards across courses, departments, and campuses through shared review tools.
Exam preparation and college applicants: Use it for timed essay practice for AP Lang, SAT, ACT, IELTS, and TOEFL, as well as polishing college application essays and scholarship essays.
Tutors and writing centers: Provide students with rubric-aligned feedback and reduce manual burden, suitable for one-on-one tutoring and ESL writing support.
Writers and writing reviewers: Use Clasa as a writing review and editing tool to conduct objective, structure-focused review of any draft's clarity, argument, evidence, and grammar.
Limitations
The materials do not provide Clasa's model details, data privacy policy, specific data on scoring accuracy, etc. Regarding the functional boundaries between the free version and paid versions, the official page mentions "free trial" and "start for free," and also lists the names, prices, and included features of paid plans such as Starter, Value, and School, but the specific availability and limitations are subject to the official latest instructions. The materials do not mention whether Clasa supports offline use or provides an API interface.
