How to Create a Multi-Line Chart in Google Slides for Year-Over-Year Comparisons

March 10, 2026

We've all been there. It’s time for the quarterly business review, and you need to show the board that your seasonal sales are actually trending up.

You want to compare January 2026 to January 2025 and 2024.

If you throw all that data into a standard bar chart, your slide instantly looks like a crowded barcode. If you use a single line chart stretching across 36 months, the seasonal spikes are impossible to compare side-by-side.

You need a multi-line chart. It overlays each year on top of the other, sharing the exact same January-to-December X-axis. It is, without a doubt, the single best way to visualize Year-Over-Year (YoY) performance.

But let's be honest. Building a clean, easy-to-read multi-line chart natively in Google Slides can be incredibly frustrating. The formatting breaks, the legends overlap, and if you need to update a single number right before a meeting, you usually have to jump back into a linked Google Sheet and pray the sync works.

There is a much easier way. Here is how to create a high-quality multi-line chart right inside Google Slides.

The Right Tool for the Job

Instead of wrestling with the native chart builder, we’re going to use ExtraChart.

ExtraChart is an add-on that lives directly inside Google Slides. It gives you 20 professional chart types, deep customization options, and completely removes the need to jump between external tools and your slide deck.

If you haven’t installed it yet, just head to Extensions > Add-ons > Get add-ons in your Google Slides menu, search for ExtraChart, and install it. It's fast, and it renders everything entirely on your client-side, meaning your private data never leaves your browser.

Step 1: Open the Multi-Series Line Chart

Once installed, go to Extensions > ExtraChart > Create & Edit Charts. The add-on will open neatly in your right-hand sidebar.

You'll see a categorized list of chart types. Scroll down to the Line & Area Charts section and click on the Multi-Series Line Chart icon.

Sidebar menu: Selecting the Multi-Series Line Chart icon

Clicking this instantly opens the ExtraChart popup editor. This is where the magic happens. You’ll see a real-time preview of your chart on the left, and your data and settings tabs on the right.

Step 2: Paste Your YoY Data

Click over to the Data tab. You’ll see a familiar, lightweight spreadsheet interface.

For a YoY comparison, your data structure should look like this:

  • Column A (Categories): Your timeframes. Usually, this is months (Jan, Feb, Mar...).
  • Column B (Series 1): Your oldest year (e.g., 2024).
  • Column C (Series 2): Your middle year (e.g., 2025).
  • Column D (Series 3): Your current year (e.g., 2026).

The best part? You don't have to type this manually. If you already have this data sitting in Excel, CSV, or Google Sheets, just highlight the cells, copy them, and paste them directly into the ExtraChart data editor.

The chart preview will update instantly.

Step 3: Design for Impact

Having the data plotted is only half the battle. A good presentation chart guides the audience's eyes exactly where you want them to go.

Click over to the Settings tab. Here are three quick design rules for YoY multi-line charts:

  1. Mute the Past: Your older years shouldn't scream for attention. Use ExtraChart's Color Palette Manager to make 2024 a light gray and 2025 a darker gray.
  2. Highlight the Present: Make your current year (2026) a bold, contrasting brand color—like a sharp blue or vibrant green. You want the audience to immediately lock onto the current performance line.
  3. Clean up the Axes: Nobody likes reading numbers like "10,000,000". Use the axis formatting controls to simplify your Y-axis to "$10M". It keeps your slide looking professional and uncluttered.

Step 4: Insert and Edit Later

Once your chart looks perfect, hit "Create".

ExtraChart will drop a crisp, high-resolution image of your multi-line chart right onto your active slide. You can resize it and drag it around just like any other image.

But here is why this workflow beats taking a screenshot from Excel: It is completely updatable.

Let’s say you get new data for Q2 right before your presentation. You don’t have to start over. Just click the ExtraChart image on your slide, open the ExtraChart sidebar, and the editor will automatically pull up your exact data and settings. Change the Q2 numbers, hit update, and the chart on your slide refreshes perfectly in place.

Stop Fighting Your Charts

Time-series comparisons don't have to be a headache. By using a multi-line chart, you immediately highlight seasonal trends and genuine YoY growth. And by using ExtraChart inside Google Slides, you save yourself hours of formatting frustration.

Give it a try on your next quarterly report. Your audience—and your sanity—will thank you.