The short answer
Sunni and Shia are the two largest branches of Islam; Ibadi Islam is another longstanding branch. A total of every sect depends on how the term is defined. Legal schools, theological traditions and Sufi orders overlap, so adding them together produces a misleading count.
Begin by asking what is being counted.
A branch is a broad historical community. A school of law develops methods for interpreting religious obligations. A theological school addresses questions about God, revelation and belief. A Sufi order organizes spiritual teaching and practice. One Muslim can belong to several of these categories at once.
This guide uses “branch” or “community” where possible. “Sect” can be an analytical term, but it can also imply that someone else’s religion is illegitimate. A useful classification explains its boundaries and allows people to describe themselves. [Historical method]
| Broad branch | A distinguishing emphasis |
|---|---|
| Sunni | The largest branch. The Prophet’s example, transmitted reports, juristic learning and the authority of the early community are central. Sunni tradition accepts the first four caliphs as legitimate. |
| Shia | The Prophet’s family, especially Ali and the imams, has distinctive religious authority. Communities differ over the succession and role of these leaders. |
| Ibadi | A distinct tradition with its own history, jurisprudence and teachings about legitimate leadership. It is especially associated with Oman, with communities elsewhere. |
Why did the communities separate?
Disputes over leadership after Muhammad’s death in 632 were foundational. The relationship between political leadership and religious authority became especially important. Later conflict, teaching networks and legal argument helped shape enduring identities. Describing the whole process as a single vote or a permanently settled split in 632 leaves too much out. [Sagha]
Within Shia history, disagreements over succession also mattered. Farhad Daftary explains how competing claims to the imamate contributed to the emergence of different communities. Their histories involve ideas about authoritative guidance as well as family relationships and political circumstances. [Daftary]
Ibadism has its own development and should not disappear into a two-branch diagram. A broad introduction can identify three major historical strands without claiming that every Muslim movement fits neatly within them. [Ibadi history]
How do the main Shia branches differ?
Three principal Shia branches are Twelver, Ismaili and Zaydi. These names identify different understandings of the imamate, not three different Qur’ans. [Shia histories]
| Tradition | A central distinction |
|---|---|
| Twelver | Recognizes a succession of twelve imams. The twelfth is believed to be in occultation, or concealment, with an expected return. |
| Ismaili | Follows a different succession after Ja‘far al-Sadiq. Ismaili communities themselves have further branches and different arrangements of religious authority. |
| Zaydi | Developed a distinct understanding of qualified leadership among descendants of the Prophet’s family, with its own legal and theological history. |
Are the four Sunni legal schools four sects?
Hanafi, Maliki, Shafi‘i and Hanbali are four major Sunni schools of jurisprudence. Their differences concern how legal reasoning works and how evidence is weighed in particular questions. Their recognition within Sunni Islam makes “four separate religions” a poor description. [Legal schools]
A difference in a detail of worship or legal practice does not automatically indicate a different branch. Ask whether the disagreement concerns a legal ruling, a doctrine, an institution or a claim to leadership. These are related questions, but the labels are not interchangeable.
Sufism is a further example of overlapping categories. The Pluralism Project describes it as a stream of interpretation and spiritual practice, with orders organized around teachers. It should not simply be counted as a fourth branch alongside Sunni, Shia and Ibadi. [Sufism]
What about the claim that there are 73 sects?
A report attributed to Muhammad in Sunan Abi Dawud 4596 predicts that his community will divide into seventy-three groups. That is a transmitted religious report. It is not a modern demographic survey, a list of seventy-three present-day organizations, or an agreed system for classifying every Muslim today. [Read the report]
The number’s religious interpretation and the task of counting living communities need separate treatment. Before accepting a numerical claim, ask who compiled the list, which groups it includes, whether historical and current groups are mixed, and whether overlapping schools have been counted twice.
What do scholars explain differently?
Religious scholars ask which teachings and authorities are sound within a tradition. Historians also examine how labels, institutions and boundaries developed. These approaches can overlap. A scholar’s religious identity alone does not establish the quality of an argument.
In his Harvard discussion of sectarianism, Mohammad Sagha cautions against treating inherited categories as simple descriptions of every period. Farhad Daftary’s account explains Shia diversity through the development of the imamate. Read each argument at the level it addresses: a history of institutions is not automatically a verdict on divine guidance. [Sagha] [Daftary]
For a practical comparison, ask: Who may interpret the sources? Which reports are accepted? How are disagreements resolved? What do members of this community say about their own belief? Then compare a named source with a serious alternative. See the worked interpretation studies for examples.
What this establishes, and what it does not
This is an introductory map of selected historical traditions. It does not enumerate every movement, decide who is entitled to call themselves Muslim, or imply that all members of a community hold identical views. Shared scripture can coexist with substantial disagreement about authority and interpretation.
Sources & reading notes
- Mohammad Sagha, “Myths of Sects and Sectarianism in Islam” (Harvard Divinity School, 2024)Academic lecture delivered 4 December 2023; transcript published 22 March 2024. Supports the discussion of changing identities, succession and the limits of imported categories.
- Farhad Daftary, “What is Shi‘a Islam?”Institute of Ismaili Studies. An account of the imamate and Twelver, Ismaili and Zaydi histories; read with awareness of its institutional setting.
- “The Interpretation of Islam under Sultan Qaboos,” in Sultan Qaboos and Modern Oman, 1970–2020Academic historical account identifying Ibadism as a distinct branch and describing its Omani setting.
- The Pluralism Project: FiqhIdentifies the four major Sunni legal schools.
- The Pluralism Project: SufismExplains the distinction between a spiritual stream, an order and a sect.
- Sunan Abi Dawud 4596Primary transmitted report behind the seventy-three figure. The linked grading is attributed to a named authority; citing it is not an independent authentication.
Sources checked 20 October 2026. Original editorial explanation; independent specialist review remains pending. Citing a scholar does not imply their endorsement of this site.