What Sparks Joy…
Sparklines are compact charts made for visual data representation. They’re usually created to show trends in a series of values, like economic cycles, seasonal changes, and highlight outlying or minimum and maximum data points.
Sparking Details--Background & Example
Hey, I Know You–Line Charts vs. Sparklines
A sparkline chart has many of the attributes of a line chart, with a few exceptions. One of them is that multiple sparklines aren’t plotted on a pair of axes. Instead, they’re stacked vertically.
Another difference lies in the number of elements found on the two kinds of charts. That’s because a sparkline’s subplot contains only the core elements. In fact, you may even find sparklines with only a line to emphasize the pattern between the values of a series.
Instant Love–Why Tufte Created Sparklines
When Tufte came up with these small charts, he intended for them to be used to provide contextual info but in a compact manner. And that’s what they do!
A spark line chart:
- Can be small enough to be placed within cells on Excel sheets, inline with the text, and stacked vertically.
- Are usually left unlabeled.

Try to Understand–An Example
I decided to base the example on a movie cliché that’s always stuck in my craw. Imagine a scene where two people are sitting at a breakfast table groaning with all kinds of delish nom noms. They argue, and then, one–and sometimes, even both–just up and leave. We’re never told what happens to the meal. And I keep thinking, how can anyone just walk away from such breakfasty goodness? The sheer number of such meals wasted makes me mad and snacky! My solution was to first make several sparkline charts on movie clichés. And then I ordered the biggest, crumbliest, chewiest, and yummiest white chocolate cookie I could find for myself!
The Best Laid Gleams—Typical Sparkline Elements
The simplest way to describe sparkline function would be to say a graphic that conveys a lot of information but doesn’t take up much space.
Now, let’s look at the elements typically found in these charts:
- A line graph showing how values change with time.
- A short title–no longer than three words–to explain what the graph’s measuring.
- A number showing the final/total result arising from the changes.
You can add other details, but sparklines are best kept simple and uncluttered.
Sparkle Takeover—Use Cases
Wondering what does a sparkline chart show? Sparkline graphs may be distant cousins of line graphs, but they are ubiquitously used in many sectors.
Some examples include:
1. Education sector - Since it’s easy to insert these charts in line with accompanying text, they are often embedded in textbooks and other academic documents. The information graphically shown in a sparkline illustrates the text appearing directly before or after. In other words, readers can view the trend displayed in the graphic without interrupting their reading. Multiple line charts in one plot–one for every metric–can consume more space. That’s because those come with repeated labels of horizontal axes values. That may not work with documents like theses and dissertations since they have a fixed page range. This is something you won't require with a sparkline.
2. Corporate sector - A chart type that effectively and quickly communicates trends across KPIs. Here, too, its context is a part of the surrounding text.
3. IT sector - You may already have come across sparklines on different dashboards. These foundational pieces are ideal as starting points for end users.
In the Grand Gleam of Things—Most Common Uses
We’ve discussed three scenarios where sparkline charts can play a part in data visualization. Now, let’s peek at what makes them best suited for such purposes and why:
- The chart below shows how cramped multiple line plots can get. What if we stacked seven sparklines to display the same data? How about doing that inside a table to facilitate quick comparison? Sparklines work well as alternatives for line charts when plotting multiple lines. Mainly, that’s because they’re great for showing changing values over time, just as line charts are.

- Another great use of sparklines is based on data type. Plotting a line graph with overlapping values can make it difficult for readers to distinguish one series from another. Case in point, more movie clichés you can see below:




- Likewise, sparklines are also a better choice for displaying data with no overlap. For instance, say you’re tracking multiple metrics simultaneously. If you display such data on a line chart, it may hide changes due to the different scales of the different lines. Sparklines, though, can cover broadly different ranges. Each metric has its own scale (vertical) but maintains its alignment (horizontal) for easy viewing. Unlike a multi-axis plot, your viewer won't have to associate each line with its scale.

I’d still call this a good score. Wouldn’t you?
- Some data sets contain outliers while others have distinct high-low points. It’s easier to point out those areas to your readers when you use a sparkline in your reports or dashboard, such as the last or lowest/highest value to date or the ensuing trend and whether it’s increasing or decreasing. For instance, the graph below marks the very special occasions–read only two–when I’ve known something more than my Mom about a topic. The spikes in the sparkline make tracking down both times much easier.
A Spark Reminder—Best Use Cases
You may already be familiar with our guidelines for producing excellent line charts. Let’s check which of the following applies to a sparkline as well:
And keep talking that mess, that's not fine
Don’t use sparkline without considering its tradeoffs. For instance, the vertically narrow subplot limits how much info you can show for each set. There also won’t be any reference markings other than the start and end values. So, don’t use a sparkline to emphasize absolute changes or situations that call for quantitative scrutiny. Instead, leverage them to highlight the relative changes and qualitative inspection.
But could you draw and talk at the same time?
Sure, charts are visualizing data tools and sparklines are no different. However, they exert maximum impact when supplemented with text for context and additional meaning.
And it's my graphical elements that is on that tag
Just as placement matters for line charts, don’t inundate your sparkline chart with numerous graphical elements like keys, symbols, legends, and titles. Since you’ll probably opt for this chart type for its minimalist design, make the most of it by keeping things uncluttered.
So add your tables let me call you a cab
Data presenters choose a sparkline chart to avoid the traffic jam that a multi-axis line plot would make due to too many data points. However, don’t forget to add a table with your sparkline’s data to up its reader-friendliness.
Recap–Inspired by Queen B’s Irreplaceable
And keep talking that mess, that's not fine
But could you draw and talk at the same time?
And it's my graphical elements that is on that tag
So, add your tables let me call you a cab
Putting the Spark in Sparkline—Product Details
If you’re falling for sparklines the way I and the rest of the Image Charts team did when we discovered them, you’ll be itching to try them out. Displaying a boatload of values, such as for stock exchange, temperature, KPI trends, etc., looks so much prettier and more easily interpretable with these charts. And once you learn to create and automate them through Image Charts, you’ll be a lifelong fan of both.
Here are several things you can play with when creating a sparkline via Image Charts:
- Those wondering how to change sparkline color will appreciate this Image Charts feature.
- Display your data using the line thickness and styles and chart sizes of your choice.
- Receive sufficient oohs and aahs by sharing your sparkling creations with friends and coworkers through Visualforce, MailChimp, Email, Team, Slack, and Zapier.
- Impress by presenting chart-turned-gifs.
Your Time to Shine—How Image Charts can Help
Automation
Image Charts automation is a godsend for people who regularly present data as part of their profession or for academic purposes. Once you link your Image Charts profile with either Zapier or Make, you can put your data troubles to rest because:
- The workflow will keep extracting data from the source and feed it to Image Charts for automated chart creation.
- You can use one of the many–and there are many–vehicles to distribute your brand new charts.
View the platform-specific guidelines for automation below:
Zapier
- Begin a Trigger by picking your data source, anything from Email to CRM.
- Let Zapier connect to Image Charts, so you can select your sparkline options
- Now choose where you want your chart to go and send it through the URL received.
Make
- Locate your data source.
- Connect Make to Image Charts and select chart features.
- Learning how to add a sparkline is simple: pick your distribution vehicle, paste in the URL, and forward.
API
Want to create a line sparkline with the Image Charts API? Write sparkline URL formulas with Image Chart’s API option:
- Start with this part: https://image-charts.com/chart
- Use ?cht=ls to specify your chart type
l is for line chart
s represents sparkline
- Experiment with size via &chs=700x100
700 is the width (in pixels)
100 is the height (in pixels)
- Define the chart value to this part of the URL formula: &chd=t:60,40
- Finally, add axis labels with &chxl=0:|Jan|Feb|Mar|Apr|May|Jun
Now paste your URL formula into your browser.
Need more? Your detailed instructions are here.
Keeping the Sparks Alive
We’ve covered several areas regarding sparklines, including what is a sparkline, what their function is, and when to use them for maximum impact. Start using this understated Image Charts feature for aesthetically pretty data presentation. Sparkline charts, ahoy!
The Glitter Truth--FAQs
1. How do you write sparkline formulas in Image Charts?
The Image Charts API option simplifies sparkline URL formulas. That’s because most of its elements are the same for all chart types. Follow this workflow to write one today!
2. How do you edit sparklines in Image Charts?
Editing your sparkline will involve tweaking the values in the URL formula given above.
3. How many colors can an Image Charts sparkline have?
Since your sparkline will consist of a single line, it can only be in one color. The same will apply to line thickness and style. However, you may vary these characteristics between different sparklines in the same stack. Both sparkline excel and sparkline google sheets work similarly.
Read more about sparkline charts in our documentation here.