Short answer
Partly. Avoiding clear mistakes that change a letter, a vowel or the meaning is obligatory for every reciter, so basic tajweed is required. The finer rules, such as exact lengths and nasal sounds, are recommended and their mastery is a communal duty. You can memorise while still learning, but get your reading checked first.
Correct pronunciation of the letters and vowels so that the words are not changed (avoiding al-lahn al-jali) is fard for whatever you recite, especially in salah. The detailed rules (al-lahn al-khafi) are sunnah or mustahabb for the individual and fard kifayah for the community to preserve.
The four schools agree on this.
Explanation
Tajweed means reciting each letter from its proper place with its proper qualities. Allah commands the Prophet ﷺ to "recite the Quran with measured recitation" (73:4), and Ali explained tartil as giving the letters their due and knowing where to stop.
Scholars of recitation split mistakes into two kinds:
- Clear mistakes (lahn jali): turning one letter into another, such as the deep throat ha into an ordinary h, ayn into alif, or changing a vowel. These can change the meaning, so avoiding them is obligatory. Some can even break the prayer: see mistakes in recitation in salah.
- Hidden mistakes (lahn khafi): missing an exact length of madd, a light nasal sound or a fine quality of a letter. They do not change the meaning. Perfecting these is recommended and a mark of excellence.
All four schools agree in substance. Ibn al-Jazari, the great scholar of recitation, wrote that applying tajweed is necessary, and the scholars explain this mainly as the first level.
Memorising without tajweed? You can start memorising while learning, but mistakes memorised are hard to undo, so learn the letters and vowels well first and recite to a teacher regularly. A non-Arab who tries hard and still struggles is not blamed: the Prophet ﷺ promised two rewards to the one who finds the Quran difficult. Start with the Noorani Qaida and tajweed rules.
The evidence
Quran, Surah Al-Muzzammil 73:4
أَوْ زِدْ عَلَيْهِ وَرَتِّلِ ٱلْقُرْءَانَ تَرْتِيلًا ﴿٤﴾
Or add to it, and recite the Qur'an with measured recitation.
The command for careful recitation that tajweed puts into practice.
Sahih Muslim 798
Sahih... الماهر بالقرآن مع السفرة الكرام البررة ...
"The one skilled in the Quran is with the noble and righteous scribes, and the one who stumbles over it with difficulty has two rewards."
Effort in learning is rewarded even before mastery.
Where the ruling is recorded
- al-Muqaddima al-Jazariyya (Ibn al-Jazari), Section on the obligation of tajweed. Applying tajweed is necessary for the reciter.
- Radd al-Muhtar (Ibn Abidin), Kitab al-Salah, chapter on the errors of the reciter. Which errors in letters change the meaning and affect the prayer.
Checked by our team. For a more accurate answer to your own situation, consult a scholar. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.