Short answer
No, taraweeh is prayed after Isha. Rakat prayed before Isha do not count as taraweeh. If you arrive while the imam is already in taraweeh, first pray Isha (and its sunnah) on your own, then join, and make up the taraweeh rakat you missed. You may join the imam for witr and complete the rest of taraweeh afterwards.
The time of taraweeh is after the fard of Isha until dawn, in the relied-upon view. Taraweeh prayed before Isha is not taraweeh. A latecomer prays Isha first, then joins; missed rakat may be completed after witr.
The four schools agree on this.
Explanation
Taraweeh follows Isha in the same way the sunnah of Isha does. The Hanafi texts give its time as after the obligatory Isha prayer until true dawn. Anything prayed before Isha is ordinary nafl, not taraweeh.
If you arrive late at the masjid:
- Pray the four rakat of Isha fard on your own, in a corner or a side room, then the two sunnah if you can.
- Join the imam in taraweeh wherever he is.
- If the imam reaches witr before you have finished taraweeh, you may join him for witr in congregation.
- Then pray the taraweeh rakat you missed, two at a time, after witr. The Hanafi texts allow taraweeh after witr.
Do not join the taraweeh with the intention of Isha. In the Hanafi school a person praying an obligatory prayer cannot follow an imam who is praying a sunnah, so your Isha would not be valid.
If you prayed Isha and later realised it was invalid, for example you had no wudu, you repeat Isha and then repeat the taraweeh you prayed after it, because that taraweeh was prayed before a valid Isha.
The Prophet ﷺ said that whoever stands with the imam until he finishes is recorded as having stood the whole night, so try to arrive before Isha. For how taraweeh is prayed, see how to pray taraweeh, and for its latest time see the time for taraweeh.
The evidence
Quran, Surah Al-Israa 17:78
أَقِمِ ٱلصَّلَوٰةَ لِدُلُوكِ ٱلشَّمْسِ إِلَىٰ غَسَقِ ٱلَّيْلِ وَقُرْءَانَ ٱلْفَجْرِ ۖ إِنَّ قُرْءَانَ ٱلْفَجْرِ كَانَ مَشْهُودًۭا ﴿٧٨﴾
Establish prayer at the decline of the sun [from its meridian] until the darkness of the night and [also] the Qur'an of dawn. Indeed, the recitation of dawn is ever witnessed.
Each prayer has its time, and taraweeh is tied to the time after Isha.
Jami' at-Tirmidhi 806
Grading to be checked... إنه من قام مع الإمام حتى ينصرف كتب له قيام ليلة ...
"Whoever stands in prayer with the imam until he finishes, a whole night of prayer is written for him."
There is great reward in praying taraweeh with the imam from start to finish.
Where the ruling is recorded
- al-Durr al-Mukhtar, Kitab al-Salah, chapter on witr and nawafil, section on taraweeh. The time of taraweeh is after Isha until dawn, and it is valid before or after witr.
- Radd al-Muhtar (Ibn Abidin), Kitab al-Salah, chapter on witr and nawafil, section on taraweeh. Taraweeh prayed before Isha, or after an Isha found to be invalid, is repeated.
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.