Short answer
You can pray istikhara at any time of day or night except the times when prayer is forbidden or disliked. Pray two rakats of nafl, then read the istikhara du'a. Many people prefer the night, before sleeping or at tahajjud, but that is not required, and you do not need to see a dream.
Salat al-istikhara is sunnah: two nafl rakats followed by the du'a taught by the Prophet ﷺ, for any permissible decision. It is prayed outside the makruh times. If you cannot pray, you may read the du'a on its own.
The four schools agree on this.
Explanation
Istikhara means asking Allah to choose what is good for you. The Prophet ﷺ taught it to his Companions "as he taught them a surah of the Quran", for every kind of matter. The four schools agree that it is sunnah and that it is done for permissible choices, such as a job, a move, a purchase or a marriage proposal. You do not do istikhara about whether to pray or whether to do something haram.
- When: any time outside the forbidden and disliked times: sunrise, midday (zawal), sunset, after the Fajr fard and after the Asr fard. See the forbidden times.
- How: two rakats of nafl with the intention of istikhara, then the du'a, naming your matter where the du'a says "this matter".
- Best time: many prefer the night because the heart is calmer, but no time is required.
- Repeating: you may repeat it on several days if you are still unsure.
What happens after? You do not need a dream or a sign. Go ahead with what your heart leans to, and if things become easy, take it as good. If the matter is closed to you, accept that as the answer. Scholars also advise istishara (asking people of good sense) alongside istikhara.
A woman in her period, or anyone who cannot pray, may read the du'a alone. The full Arabic du'a and the method are in our guide to the istikhara dua.
The evidence
Quran, Surah Aal-i-Imraan 3:159
فَبِمَا رَحْمَةٍۢ مِّنَ ٱللَّهِ لِنتَ لَهُمْ ۖ وَلَوْ كُنتَ فَظًّا غَلِيظَ ٱلْقَلْبِ لَٱنفَضُّوا۟ مِنْ حَوْلِكَ ۖ فَٱعْفُ عَنْهُمْ وَٱسْتَغْفِرْ لَهُمْ وَشَاوِرْهُمْ فِى ٱلْأَمْرِ ۖ فَإِذَا عَزَمْتَ فَتَوَكَّلْ عَلَى ٱللَّهِ ۚ إِنَّ ٱللَّهَ يُحِبُّ ٱلْمُتَوَكِّلِينَ ﴿١٥٩﴾
So by mercy from Allah, [O Muhammad], you were lenient with them. And if you had been rude [in speech] and harsh in heart, they would have disbanded from about you. So pardon them and ask forgiveness for them and consult them in the matter. And when you have decided, then rely upon Allah. Indeed, Allah loves those who rely [upon Him].
Consulting people and then relying on Allah go together, which is what istikhara and istishara do.
Sunan Abi Dawud 1538
Graded sahih... إذا هم أحدكم بالأمر فليركع ركعتين من غير الفريضة ...
"When one of you intends a matter, let him pray two rakats other than the obligatory prayer."
Istikhara is two nafl rakats followed by the du'a, for any matter.
Where the ruling is recorded
- Radd al-Muhtar (Ibn Abidin), Chapter on witr and nawafil, discussion of salat al-istikhara. Istikhara is recommended, may be repeated, and one acts on what the heart inclines to.
- al-Adhkar, Chapter on istikhara. Imam al-Nawawi explains the du'a and that one acts on what the heart is at ease with.
This answer is pending review by the scholars on our team. 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.