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Also known as: Line Graph
Chart that connects ordered data points with lines to show trends, typically over time.
DESCRIPTION
A line chart visualizes ordered data by connecting points with straight segments, emphasizing trends and changes. It is ideal for continuous series and time-based data. Multiple series can be overlaid to compare categories, but clarity demands careful color and labeling choices. Use consistent scales and avoid excessive smoothing that obscures signals. Line charts are common in dashboards and KPI tracking.
ALTERNATIVE DEFINITIONS
Wikipedia
A line chart or line plot or line graph is a type of chart which displays information as a series of data points called ‘markers’ connected by straight line segments.
Defines structural elements: markers and connecting line segments.
The Data Visualisation Catalogue
A Line Graph is used to show how data changes over time or to compare multiple time periods.
Emphasizes temporal change and comparison across periods.
RELATED TERMS
Temporal Data Trend Analysis Scatter Plot Moving Average Small Multiples Dashboard Smoothing Axis Scaling
COMPETING TERMS
Bar Chart Area Chart
RELATIONS
- Broader: Chart
KNOWLEDGE AREAS
Data Visualization Data Warehousing & BI
TARGET AUDIENCE
BI Specialist Data Analyst Information Analyst
EXTERNAL SOURCES
- Wikipedia - Line chart
- Tableau - Guidance on creating and using line charts
- Data to Viz - Design choices and caveats for line charts
TOP QUESTIONS
When should you use a Line Chart?
Use it for continuous data, especially time series, to highlight trends and changes. It’s less suitable for discrete categories without inherent order.
Category: Usage
What are common mistakes with Line Charts?
Using inconsistent scales, overcrowding with too many series, or smoothing excessively can mislead. Always label axes and include units.
Category: Mistakes
How do you compare multiple series in a Line Chart?
Use distinct colors and clear legends, consider small multiples if lines overlap, and ensure shared axes for meaningful comparison.
Category: BestPractices
When is an Area Chart better than a Line Chart?
When emphasizing cumulative totals or volume under a curve; however, stacked areas can obscure individual trends.
Category: Alternatives
How to handle seasonality with Line Charts?
Overlay moving averages, show year-over-year lines, or use small multiples to reveal recurring patterns.
Category: Analysis
What is the best way to show uncertainty on a Line Chart?
Add confidence bands or error bars, or use ensemble ribbons to indicate variability.
Category: Visualization
How many series are too many for a Line Chart?
As a rule of thumb, more than 4–6 lines often reduces readability. Consider faceting or interactivity for larger sets.
Category: Design
How should line thickness and markers be used?
Use thin lines for dense data and add markers sparingly. Thicker lines can emphasize key series.
Category: BestPractices
Can Line Charts display non-time ordered data?
Yes, if the data has a meaningful order (e.g., dose-response). Without order, a bar or scatter plot may be clearer.
Category: Clarification