Short answer
Idle talk after Isha is makruh tanzihi (mildly disliked), because the Prophet ﷺ disliked talking after Isha and late chatter keeps people up so they miss tahajjud or Fajr. Talk with a need or a good purpose is fine: family time, guests, study, work or advice. The four schools agree.
Worldly chatter after the Isha prayer with no need is makruh tanzihi, as is sleeping before Isha. Talk that has a need or benefit is not disliked, such as talking with your spouse and children, hosting guests, studying, or a traveller's affairs. Sinful talk, such as backbiting, is haram at any time.
The four schools agree on this.
Explanation
The Prophet ﷺ disliked sleeping before Isha and talking after it. Scholars explain the reason: Isha is a good way to close the day, and long chatter after it pushes sleep late, so people miss the night prayer or even Fajr. The four schools agree that this is a mild dislike, not a sin.
Talk that is not disliked after Isha:
- Time with your spouse and children
- Looking after guests
- Studying, teaching or reading beneficial knowledge
- Work that has to be done, or a traveller's needs
- Giving advice or settling a problem
Is it makruh to stay up after Isha? Staying up is not haram. But if late nights, whether talking, gaming or scrolling, regularly make you miss Fajr, they have become blameworthy, because they lead to leaving a fard. The simplest sunnah is to pray Isha, wind down, and sleep, so you can wake for Fajr and perhaps for tahajjud.
Related: is it sunnah to delay Isha, sleeping after Fajr or Asr and the du'a before sleeping.
The evidence
Sahih al-Bukhari 568
Sahih... كان يكره النوم قبل العشاء والحديث بعدها ...
"He disliked sleeping before Isha and talking after it."
Idle talk after Isha is disliked.
Where the ruling is recorded
- Radd al-Muhtar (Ibn Abidin), Kitab al-Salah, chapter on prayer times. Sleeping before Isha and talking after it are disliked, except talk for a need or benefit.
- al-Majmu' (Nawawi), Chapter on prayer times. The Shafi'i school likewise dislikes idle talk after Isha and permits talk with a benefit.
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.