The charts are interactive:
- Zooming in: on timeline charts you can zoom in: use the slider (dataZoom) below the chart, scroll with the mouse wheel over the chart, or drag to shift the visible window. Comparison and exit poll charts have no zoom; their range is fixed.
- Viewing values: move your mouse over the chart (hover) to see a vertical guide line with a tooltip listing every pollster at that point, with its exact value. Individual polls show whole percentage points; where the line is drawn between two polls, the interpolated value is shown with one decimal, e.g. 2.3.
- Showing or hiding pollsters: click a name in the legend to temporarily show or hide that pollster in the chart. When many pollsters or parties are shown at once, you can scroll through the legend.
- Names next to the line: with twenty or fewer pollsters or parties in one chart, the name is shown directly at the right-hand end of each line, so you can identify a pollster without the legend.
- Records: a pin marks the highest or lowest figure a party has ever reached, or within a given period (for example the last 5 or 10 years). When viewing a single pollster's chart, the tooltip notes "according to {pollster}" — such a record only applies to that pollster, not the all-pollster average.
- Downloading: click the camera icon in the top-right of the chart to download it as an image (PNG).
If a pollster hasn't published for a long time — for example because they paused fieldwork for a period — that pollster's line is broken rather than stretched to the next available point, so the chart doesn't give a distorted impression.
Below every chart is a table with the same figures in text form: useful as an alternative overview, and as a fallback when the interactive chart itself can't load.