Short answer
Pray it like any two-rakah prayer: make the intention, say Allahu akbar, recite al-Fatiha and a surah in every rakah, and finish with salam. You may pray two or four rakats with one salam, and you may pray sitting even without an excuse, for half the reward. Avoid the times when prayer is disliked.
Nafl is prayed in units of two or four rakats, and al-Fatiha with a surah is wajib in every rakah. Each pair of rakats is treated as its own prayer, so you sit for the tashahhud after every two. Once you start a nafl prayer, completing it becomes wajib, and if you break it you make up two rakats.
Other madhhabs
- Shafi'i
- Starting a nafl prayer does not oblige you to finish it, and nafl is best prayed in pairs.
- Hanbali
- Starting a nafl prayer does not oblige you to finish it; pairs are best, by night and by day.
Explanation
Nafl means an extra prayer beyond what is required. It earns reward, and on the Day of Judgement voluntary prayers help make up for shortcomings in the fard. There is no special method: you pray it like the two rakats of Fajr, with one difference, that you recite a surah after al-Fatiha in every rakah.
- Make the intention in your heart, for example "two rakats nafl for Allah".
- Raise your hands, say Allahu akbar, and read the thana.
- Recite al-Fatiha and a surah, then ruku and two sajdahs.
- Stand for the second rakah, recite al-Fatiha and a surah, then ruku and two sajdahs.
- Sit, recite the tashahhud, the salawat and a du'a, and give salam.
- Four rakats: sit after the second rakah for the tashahhud, then stand and pray two more. Many Hanafi texts recommend reading the salawat in that first sitting and the thana again at the start of the third rakah.
- Sitting: allowed in nafl without any excuse, with half the reward of standing.
- When: any time except the forbidden and disliked times; see forbidden times.
- If you break it: in the Hanafi school you make up the two rakats you started.
Named nafl prayers have their own pages: tahajjud, ishraq and duha, salat al-hajah and salat al-tawbah. For the difference between sunnah and nafl, see the sunnah prayers.
The evidence
Jami' at-Tirmidhi 413
Grading to be checked... إن أول ما يحاسب به العبد يوم القيامة من عمله صلاته ...
"The first of a servant's deeds he will be called to account for on the Day of Resurrection is his prayer."
Voluntary prayers make up for gaps in the fard on that Day.
Sahih Muslim 735
Sahih... صلاة الرجل قاعدا نصف الصلاة ...
"A man's prayer sitting is half the prayer."
Nafl may be prayed sitting for half the reward.
Sahih al-Bukhari 990
Sahih... صلاة الليل مثنى مثنى ...
"The night prayer is two by two."
Night nafl is prayed in pairs.
Where the ruling is recorded
- al-Hidaya, Kitab al-Salah, chapter on nawafil. Nafl may be prayed in twos or fours; recitation is wajib in every rakah of nafl.
- Radd al-Muhtar (Ibn Abidin), Kitab al-Salah, chapter on witr and nawafil. Starting a nafl makes completing it wajib, and a broken nafl is made up.
- al-Majmu' (Nawawi), Chapter on voluntary prayer. In the Shafi'i school a nafl may be left without making it up.
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.