Data Line Reference
Overview
Data Line is the mirror feature to Data Bar: instead of drawing a bar per cell, it plots one point per cell and connects consecutive points with a line — producing a sparkline-like trend that runs either down a column or across a row. It shares the same value logic and table-wide scale as Data Bar (same modes, same [min, max] handling), so switching between the two is mostly a styling decision.
Location: Format pane → Data Line card → master toggle Show data lines.
A cell renders either a Data Bar or a Data Line, never both — turning one on turns the other off automatically.
Line value — what positions the point
Setting: Line value (dataLineMode) · Options: Cell Value, Compare to Regex, Follow Signif 1/2/3 Rule · Default: Cell Value
Identical semantics to Data Bar's Bar value: Cell Value follows the Value → Vertical % → Horizontal % → Indice priority from Table Content; Compare to Regex positions the point at the écart vs. a regex-matched reference column (Reference regex setting); Follow Signif 1/2/3 Rule positions it at the écart captured by that significance test, with the marker's color reflecting the test's verdict (see Significance on Charts).
Orientation
Setting: Line orientation (dataLineOrientation) · Options: Vertical lines (down rows), Horizontal lines (across columns) · Default: Vertical lines
| Orientation | One line per… | Point position in cell | Connects |
|---|---|---|---|
| Vertical lines (default) | Column | Horizontally, by value | Row N to row N+1 of the same column — a trend running down the table. |
| Horizontal lines | Row | Vertically, by value | Column N to column N+1 of the same row — a trend running across the table, broken automatically at each column sub-group boundary. |
Choose Vertical lines to see how a metric evolves as you read down the rows (e.g. one line per KPI column). Choose Horizontal lines to see, within a single row, how the metric moves across an ordered set of columns (e.g. a wave-over-wave or year-over-year trend).
Line & markers
| Setting | Type | Default | Description |
|---|---|---|---|
| Line thickness (px) | Number | 2 | Thickness of the connecting segments. |
| Show markers | Toggle | On | Draws a dot at every data point, on top of the line. |
| Marker size (px) | Number | 5 | Diameter of the marker dot. |
Zero axis
Setting: Zero axis (dataLineAxisStyle) · Same options and behavior as Data Bar's Zero axis (None, Line, Double line, Dotted line, Dashed line, Axis line) — drawn as a reference line along the value axis.
Colors
Location: Format pane → Data Line card. Which group applies depends on Grouping, below: the single-line settings only matter with no grouping, and the series settings only matter with grouping on — the visual shows/hides each group's fields automatically.
Single line (no grouping) — Series colors & Marker colors groups
| Setting | Group | Description |
|---|---|---|
| Line color | Series colors | Single color for the connecting line segments — does not vary by sign. |
| Positive marker color | Marker colors | Marker color for positive values (or positive significance in Follow Signif mode). |
| Negative marker color | Marker colors | Marker color for negative values (or negative significance in Follow Signif mode). |
| Neutral marker color | Marker colors | Marker color when the value is exactly zero (or, in Follow Signif mode, not significant). |
Unlike Data Bar, Data Line does not offer a gradient "to" color or a border toggle — the line itself is always a solid color, and only the markers carry the positive/negative/neutral distinction.
Grouped mode — Series colors group
When Group into one chart is on (see Grouping below), the Series colors group instead shows one color swatch per distinct category (e.g. Qtr1, Qtr2, Qtr3, Qtr4) — Power BI's native per-series color picker. Each category gets a default color from the report's own color palette (the same theme-aware assignment Power BI uses for any chart's legend), and you can override any of them individually by clicking its swatch; the change is saved with the report like any other formatting choice.
A category keeps the same color everywhere, even if it doesn't appear in every column-group — e.g. if one year only has Q3/Q4 while another has all four quarters, Q3 and Q4 still match the color they use elsewhere. Colors are assigned by category name, not by their position within a given group.
Color series — driving colors from a measure
Setting: Color series (dataLineColorSeries) · Format pane → Data Line card → Series colors group · Only visible when grouping is on
An alternative to manually clicking each category's swatch: pick a measure bound to the Additional Series data role (one value per category, e.g. a #RRGGBB hex string) and every category takes its color from that measure instead. Leave it on None to keep manually-picked/default palette colors. See Data Bar → Color series — same mechanism, independent storage.
📸 Screenshot — Format pane settings dataline-colorseries-settings.png (optional, still pending) — the Color series dropdown itself (single field, not the per-category swatches above), with an Additional Series measure selected.
Grouping
Setting: Group into one chart (dataLineGroupBy) · Options: No grouping, Group last-level columns, Group last-level rows · Default: No grouping
Same principle as Data Bar's Grouping: merges the last hierarchical level into a single cell, drawing one point per series (each in its own series color, see Colors above) instead of one point per individual cell, with a color legend shown under the table.
Group separators (toggle, default On) — when grouping is active, draws a subtle vertical separator at each upper-level group boundary (where the line necessarily breaks), so the break stays visually readable even with table borders turned off.
As with Data Bar, the per-test significance overlay does not apply to grouped lines — grouped points use their series color only.
See Table Headers → Hiding a header level to remove a now-redundant column or row label cleanly, instead of leaving it in place once the series legend already shows the same category names.
With Group last-level rows and 2-level row grouping (a sub-table per top-level row category, e.g. one per country), each sub-table only ever produces one merged cell per column — there's no second point in the same sub-table to connect to vertically. Connecting each series' point from one sub-table down to the next (e.g. the same year, across countries) isn't implemented yet; you get isolated points there rather than a broken line. The horizontal case (connecting across columns within one sub-table, the far more common use — e.g. a trend across years) works as expected.
Legend
Location: Format pane → Data Line card → Legend group. Only visible/relevant when grouping is on.
| Setting | Type | Default | Description |
|---|---|---|---|
| Show | Toggle | On | Shows/hides the color legend drawn below the table. |
| Sort on label | Toggle | Off | Off (default) lists categories in Power BI's own data order — the order that best matches how your query returns them. On sorts entries alphabetically by category name instead. |
| Content | Text only, Logo + Text, Logo only | Text only | What each entry shows besides its color marker: the category name, its Header Logo, or both. A category with no logo falls back to its name, so an entry is never empty; in Logo only the name stays available as a hover tooltip. |
| Position | Top left/center/right, Bottom left/center/right | Bottom center | Where the legend sits relative to the table. It aligns to the chosen edge/center on a single row (wrapping only if it's too wide to fit), rather than being confined to a fixed third of the table's width. |
Each entry's color marker is a short line (not a square, unlike Data Bar's legend), since the series are drawn as lines.
The logos come from the same Header Logos lookup (or Logo series) used for the merged level's headers. Once grouping merges that level, its header label is redundant: hide it (see Hiding a header level) and let the legend carry the logos instead. The logos stay available to the legend even when the header level is hidden.
Data Bar has its own Legend group — they don't share settings, even though only one of the two can be active at a time (see Data Bar). Set Show/Sort separately for each if you switch between them.
Troubleshooting
- Line looks broken in unexpected places → in Horizontal lines orientation, the line always breaks at column sub-group boundaries by design (it never crosses from one Level-1 group of columns into the next). This is what Group separators makes visible.
- No line at all, only markers → check Line thickness isn't 0, and that consecutive cells both have a resolvable value for the selected mode (a missing value on either side of a segment breaks that segment only).
- Markers don't reflect significance colors → confirm Line value is set to a Follow Signif Rule — in Cell Value or Compare to Regex mode, markers follow the plain positive/negative/neutral colors, not significance.