How do I make a swimmer plot from a spreadsheet?

Export or copy your table with the columns id, group, duration, ongoing and events, paste it into the box above (or upload the CSV), and the plot updates immediately. Choose the time unit and sort order, then download SVG, PNG or CSV.

How do I add response and progression markers?

Put them in the events column as CODE@time, separated by semicolons, for example PR@8;PD@30;Death@34. The time is on the same scale as duration. CR, PR, SD, PD, Death and AE have fixed shapes and colours, and the legend lists only the events that appear in your data.

What does the arrow at the end of a bar mean?

It marks a subject who is still on treatment, or still responding, at the data cut-off. The bar stops at the last observed time and the arrow shows that follow-up continues. Set ongoing to yes for those subjects.

How are subjects ordered?

By default the longest duration is at the top, the usual convention. You can also sort shortest first, group by group and then by duration, or keep the order of your input. The downloaded CSV follows the order shown on the plot.

What happens if my CSV has errors?

Rows that cannot be read, such as a missing ID, a duration that is not a positive number, or an event not written as CODE@time, are skipped and listed with their line numbers so you can fix them. If no row is valid, no plot is drawn and the downloads are disabled.

Which formats can I download?

SVG for editing in a vector tool, PNG for slides and documents, and CSV with the cleaned table in the order shown on the plot. The example data on this page is fictional and carries a footnote saying so; clear the footnote when you use your own data.

Clinical Data Tool

Swimmer Plot Generator from a CSV

Make a swimmer plot online: paste a CSV of subjects, durations, response events and ongoing flags, then export SVG, PNG or CSV. Runs in your browser.

One bar per subject, sorted by durationResponse, progression and death markersArrows for ongoing treatmentExport SVG, PNG or CSV

Subject table

One subject per line: id,group,duration,ongoing,events. Events use CODE@time separated by semicolons, for example PR@8;PD@30.

Columns: id and duration are required. group sets the bar colour (an arm, dose level, or best response). ongoing (yes/no) draws an arrow at the end of the bar. Event codes CR, PR, SD, PD, Death and AE get built-in markers; any other code gets its own marker.

TitleTime unitSort subjectsX-axis label (optional)Footnote (optional)

16 subjects · 6 ongoing · median duration 29.5 weeks

Swimmer Plot Examples

Exact renders from this generator, using fictional example data

View:

Two-Arm Response Timeline

Exact engine render from fictional example data: two arms, response markers and ongoing arrows.

two-armresponseongoing

Dose-Escalation Cohort

Exact engine render from fictional example data: bars coloured by dose level with adverse events.

dose-escalationadverse-eventcohort

What is a swimmer plot?

A swimmer plot shows the course of each subject in a study as one horizontal bar. The bar runs from the start of treatment to the end of follow-up, markers on the bar show when events happened, and an arrow at the end of a bar means that subject was still on treatment (or still responding) at the data cut-off. It is most common in oncology and early-phase trials, where a Kaplan–Meier curve hides individual stories: who responded early, who progressed, who is still being treated. Plotting every subject on one time axis makes patterns visible that a summary statistic cannot show.

How to read one

Each row is one subject, labelled with the subject ID on the left.
Bar length is time on treatment or time on study, on the x-axis in weeks, months, days or years.
Bar colour shows a grouping such as treatment arm, dose level, or best overall response.
Markers show events at the time they occurred, for example a complete response, partial response, progression, adverse event or death.
An arrow at the end of a bar marks treatment that is ongoing at the cut-off, so the true end of that bar is still unknown.
Subjects are usually sorted by duration so the longest bars sit at the top and the plot reads like a staircase.

Data format for this generator

Header row with id and duration (required), then optional group, ongoing and events columns.
id: any text label for the subject, for example P-01. Use unique IDs.
duration: a positive number in the unit you select. Time on treatment or time on study, whichever your figure shows.
group: any text. Each distinct value gets its own bar colour.
ongoing: yes or no (1 or 0 also work). Yes draws the end-of-bar arrow.
events: a semicolon-separated list of CODE@time, for example PR@8;CR@24;PD@38. CR, PR, SD, PD, Death and AE use built-in markers. Any other code is drawn with its own shape and listed in the legend.

Swimmer plot vs Kaplan–Meier and forest plots

A Kaplan–Meier curve summarises a whole group: the probability of staying event-free over time, with censoring ticks. A swimmer plot keeps every subject separate, so you can see the response timing and the ongoing cases behind that curve. A forest plot sits one level higher still, pooling effect sizes across studies. Many clinical papers and slide decks use all three: swimmer plot for individual courses, Kaplan–Meier for the group-level time-to-event, and forest plot for the pooled estimate.

Using it responsibly

This tool draws the data you give it. It does not check response criteria, derive best overall response, or compute any statistic, and it is not a validated clinical-programming environment. Check durations, event times and ongoing status against your source data before you use the figure, and follow your sponsor, journal or regulator rules for any figure that goes into a submission. The data stay in your browser; nothing in the table is uploaded to draw the plot.

Frequently Asked Questions

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