# Explore and visualise

Admins and members in Kontala can explore.
Viewers can open dashboards and saved charts.

## Build a chart

1. Open an [explore](/docs/analytics/explores), such as **Visits**.
2. Pick the [dimensions](/docs/analytics/dimensions) and [metrics](/docs/analytics/metrics) you want.
3. Add filters, then run the query.
4. Choose a chart type, then save the chart to a space.

The **SQL** card shows the query each result came from.

## Filters

Filters on dimensions and filters on metrics each form their own group, and every group must match.
Within a group, choose **All** to require every condition, or **Any** to require at least one.
Text can equal, start with, end with or include a value, numbers can be compared, and dates can be in the past or next number of days, in the current period, between two dates, or in the period to date.

## Table calculations

Add calculations on top of the results, written like spreadsheet formulas, or from templates: % change from previous, % of previous value, % of column total, rank in column, running total and window functions.
See [table calculations](/docs/analytics/metrics#table-calculations) for how to add one.

## Custom fields

- Group a number into [bins](/docs/analytics/dimensions#group-numbers-into-bins) of a fixed width, a fixed number of bins, or your own ranges.
- Add a [custom metric](/docs/analytics/metrics#custom-metrics) built from a dimension.
A number can be summed, averaged, counted, or given its minimum, maximum, median or a percentile.
Text and dates can be counted, counted once per distinct value, or given their minimum or maximum.
True-or-false fields can be counted.

## Period comparison

Add a period comparison from a results column, to put each value next to the same day, week, month, quarter or year before.
It is in beta.

## Chart types

Table, Bar chart, Horizontal bar chart, Line chart, Area chart, Scatter chart, Pie chart, Funnel chart, Treemap, Gauge, Sankey, Map and Big value.
For anything else, **Custom** takes a Vega-Lite specification.
Tables and big values support conditional formatting.

## Underlying data

Click a value to see the rows behind it, or to drill into it.

## Version history

Charts and dashboards keep their versions.
Open **Version history** from a chart's or dashboard's menu to see and restore an earlier one.

## Limits

- A query returns up to 5,000 rows.
- A query can read up to 500 MB of data.
If it would read more, narrow its date range or filters.
- Weeks start on Monday.