Watch every major pandemic spread across the map
42 pandemics and major epidemics over 2,400 years. Pick one, press play, and follow where it went, how fast, and how many lives it took.
2,400 years of outbreaks
Each circle is one outbreak, placed at the year it began. Bigger circles mean more deaths. Dashed circles have no reliable death count. The scale stretches as it nears the present, because records get better. Select a circle to load it on the map.
Which were the deadliest
The dot marks the figure most often used. The band shows how far estimates differ. The scale jumps by tens so that outbreaks of a few hundred deaths and of a hundred million fit on one chart.
All outbreaks
Select a column heading to sort. Select a row to load it on the map.
| Disease | Type | Data |
|---|
About the data
Numbers for old pandemics are estimates, and honest sources disagree. This site shows the range and says how each figure was reached.
Three grades of data
CountedCases and deaths were recorded as they happened and reported to health agencies. Counts still miss people who were never tested.
EstimatedResearchers worked the total out afterwards from death records, surveys or samples. Expect a range.
ReconstructedHistorians pieced the picture together from letters, chronicles, tax rolls, burial registers and, more recently, DNA from skeletons. Treat totals as rough.
How to read the maps
For COVID-19, mpox, SARS, MERS and Ebola, colours show reported case numbers for each country at each point in time.
For older outbreaks, a dot appears when the disease is recorded at that place, and a country shades in when it was first reached. The depth of colour is an estimate of how severe the toll was there. These maps are reconstructions.
Modern borders are drawn on every map so you can find your way. They did not exist at the time, and a whole country shading in does not mean every part of it was affected.
Arrival dates come from the sources listed under each outbreak. The four severity levels are this site's own rough grading, based on the death rates those sources report. They are not taken from a single published dataset.
Pandemic or epidemic
A pandemic is a disease that spreads across several continents at once. An epidemic is a large outbreak in one region. The site includes both and labels each one.
Long-running diseases that are always present, such as malaria, tuberculosis and smallpox across the centuries, are not included, even though they have killed more people than most pandemics.
Share of the world's people
To compare across centuries, deaths are also shown against the number of people alive at the time. Population figures are rounded and follow the long-run estimates compiled by Our World in Data from the HYDE historical database and the United Nations. For outbreaks that lasted decades this is only a rough guide.
Main data sources
The sources for each outbreak are listed beneath its map. Across the site they come from: World Health Organization. UNAIDS. Johns Hopkins University. Our World in Data. European Centre for Disease Prevention and Control. Pan American Health Organization. US Centers for Disease Control and Prevention. Published historical research, listed under each outbreak. Map shapes from Natural Earth.
Figures last checked in November 2026.