O-NET

Overview

O-NET (Ordinary National Educational Test) is Thailand's standardised national achievement test, run by the National Institute of Educational Testing Service (NIETS), a public organisation under the Ministry of Education. It is given once a year to students finishing Grade 6 (Prathom 6), Grade 9 (Mathayom 3) and Grade 12 (Mathayom 6) in both public and private schools, and is built around the Basic Education Core Curriculum (B.E. 2551 / 2008). Around two million students sit O-NET each year across the three grade levels. It is a school-administered test: students do not register individually, and there is no candidate fee.

Who can apply

O-NET is taken by students at three points in Thailand's basic education system:

• Grade 6 (Prathom 6) - end of primary school.

• Grade 9 (Mathayom 3) - end of lower secondary school.

• Grade 12 (Mathayom 6) - end of upper secondary school.

Schools enter their own students; there is no separate individual application. Taking the test has become voluntary in recent years rather than a strict condition of moving to the next stage, but most schools still enter their students because the results feed into school- and national-level performance reporting.

Exam pattern

The subject list was cut down from an earlier eight-subject version (which also covered Health and Physical Education, Art, and Career and Technology) to reduce the load on students; Grade 6 and Grade 9 now sit four subjects each, and Grade 12 sits five. NIETS has also been piloting a revised "O-NET Plus" format on a voluntary basis, aimed more at diagnosing learning gaps than at ranking students; check NIETS's current-year announcement for which version applies in a given school year.

Marking and results

Each subject is scored on a 0-100 scale. Scoring is criterion-referenced against the national curriculum standards for that grade and subject, not a simple ranking against other students. NIETS publishes national, regional and school-level average scores after each sitting, and individual students can look up their own score once results are released. There is no overall pass/fail certificate tied to O-NET: it functions as a diagnostic and system-monitoring measure rather than a qualifying exam for finishing a grade level.

Important dates

O-NET for Grade 6 and Grade 9 is typically held in late January or early February, with Grade 12 usually sat slightly earlier in the same testing season; for the 2026 testing round, the Grade 6 sitting was reported for 31 January 2026. Results are generally released around four to six weeks after the test date. Exact dates move from year to year and are announced on the NIETS website and through schools; schools handle all registration and scheduling with NIETS, so students should confirm the current year's dates through their own school.

How to apply

Students do not apply individually. Schools register their own Grade 6, Grade 9 and Grade 12 students with NIETS ahead of each year's test, and NIETS allocates test centres and seating through the school. Students should check with their school for the testing date, venue and any documents (such as a student ID) they need to bring on the day.

After the exam

For Grade 6 and Grade 9 students, O-NET results are mainly used as a system-level and school-level measure of learning outcomes, alongside a student's own record of progress; they are not a graduation requirement. For Grade 12 students, O-NET was dropped from Thailand's centralised university admission system (TCAS) around 2022: TCAS now runs mainly on the Thai General Aptitude Test (TGAT) and Thai Professional Aptitude Test (TPAT), together with portfolio, quota and direct-admission routes set by individual universities. Some university programmes may still ask to see a Grade 12 O-NET result as supporting information, but it is no longer a required input to the national TCAS ranking.

Preparation tips

• Work through NIETS's released past O-NET papers and answer keys for the relevant grade and subjects; the question style repeats from year to year.

• Focus revision on the core curriculum for the subjects actually tested at your grade (four subjects at Grade 6 and Grade 9, five at Grade 12) rather than the full school syllabus.

• Since scoring is against curriculum standards rather than a ranking, prioritise understanding weak topics over trying to out-score classmates.

• Confirm the current year's test date and any format changes (such as a voluntary "O-NET Plus" option) with your school well before the testing window.

FAQs