Everything this site is built on, in one register: every live feed, dataset, scripture, scholarly work and image. Each entry names what it feeds, how it is accessed, and what is wrong with it. A site that grades other people's evidence has to publish its own.
Every portrait on this site is a halftone derivative of a Public Domain or Creative Commons image hosted on Wikimedia Commons. No press, wire service or agency photograph is used, in original or derived form. Where a licence requires attribution, it is given here and in the card the image appears in. Derivatives of share-alike originals carry the same licence as the original. Entries with no acceptably licensed image render a geometric mark instead.
How demographic figures are ranked where two credible bodies disagree. Where no figure exists, the cell says so.
Post-1900 counts and surveys: Pew, national censuses, US Religion Census / ARDA, MuslimsInBritain.org.
1 AD–1900 scholarly reconstruction: Johnson / World Christian Encyclopedia, Stark, Bulliet, Vryonis.
A reconstruction built on partial census returns. Carries reconstruction weight, not census weight.
Pre-1 AD. Region shapes and a labelled range only — no numeric adherent figure is defensible.
A published forward model, not an observation. Dated to the model, not to the year.
As stated on the congregation plate, for the bodies whose counts it renders.
Granular denominational self-report aggregated to a continuous global series from AD 33.
KNOWN CRITICISM — Counts adherents generously; its China estimates run far above Pew's.
Transparent country-by-country composition estimates with published methodology.
KNOWN CRITICISM — The 2020 China methodology change — now formal zongjiao self-identification — creates discontinuities with Pew's own earlier figures. Sikhs, Jains and Bahá'ís are bundled into 'other religions'.
An exponential model at roughly 40% growth per decade.
KNOWN CRITICISM — Criticised for assuming a constant rate and for leaning on the Mormon growth analogy.
Onomastic conversion curves built from biographical dictionaries.
KNOWN CRITICISM — Small samples; assumes the first non-Arabic name in a lineage marks the convert.
Foundational reconstruction of Byzantine decline and Islamization from Ottoman registers.
KNOWN CRITICISM — The decline paradigm is contested — Peacock, De Nicola & Yıldız (2015) argue gradual syncretic conversion.
The standard annual Jewish demographic series.
KNOWN CRITICISM — The conservative 'core' definition differs materially from the 'enlarged' definition used by the JPPI. Both are rendered here; neither is averaged.
Full-population self-report at a fixed date.
KNOWN CRITICISM — Many omit religion entirely — the US census never has. China undercounts. Nigeria's 1973 religion census was suppressed over falsification allegations.
The most extensive US count: 372 bodies reporting congregations and adherents.
KNOWN CRITICISM — Denominational self-report; COVID hampered the 2020 non-Christian counts, which are likely undercounts.
The de facto UK mosque registry, privately maintained and landmarked.
KNOWN CRITICISM — Broad definition of 'mosque' — prayer rooms and shared spaces included. No official status; there is no ONS count.
Expert-crowdsourced coding of historical polities.
KNOWN CRITICISM — Coding subjectivity and uneven coverage across regions and periods.