Substack Image SEO: Simple Tweaks That Help Your Posts Rank Higher
You already spend time on your ideas, your headline, your hook.
But how much attention do you give to your images?
If you are like most Substack writers, you drag in a nice photo, hit publish, and move on. That works fine for regular readers, but it quietly leaves search traffic on the table. Substack image SEO is one of those small, boring topics that quietly boosts the reach of every post you publish.
The good news: you do not need technical skills. You just need a few habits you repeat every time you upload an image.
Let’s keep this simple and practical.
Why Images Matter For Substack SEO More Than You Think
Google does not just read your headline and text. It also tries to understand your images. When it can understand them, your post can show up in both regular search and Google Images.
Images help in three ways:
- They give Google extra clues about your topic.
- They keep readers on the page longer, because your post feels easier to read.
- They can rank on their own in image search and send people straight to your newsletter.
Google explains how it reads images in its own guide, which is worth skimming once: Google image SEO best practices. Substack already hosts and sizes images well, so your main job is to name them clearly, describe them well, and place them in smart spots inside your post.
Think of each image as a tiny signpost that tells Google, “This post is about this topic.” Your job is to write the sign.
Start Before You Upload: Smart Image File Names
Most images start life as something like IMG_4829.jpg. That tells Google nothing.
A better file name is short, clear, and close to your post topic. You only need 3 to 5 words, with hyphens instead of spaces.
Simple rule:
Describe the image in plain language, and include one main keyword from your post.
Real filename examples for typical newsletters
| Newsletter type | Bad filename | Better filename |
|---|---|---|
| Writing tips | IMG_2039.jpg | writing-habit-morning-routine.jpg |
| Solo business | screenshot-final.png | substack-pricing-page-example.png |
| Culture essay | photo1.png | indie-bookstore-reading-corner.jpg |
| Tech / AI | graph.png | ai-tools-comparison-chart-2025.png |
See the pattern? Short, specific, human.
On your laptop, rename images before you drag them into Substack. It adds 10 seconds and pays you back for years.
If you want a broader view of what helps posts rank, Robin Kai’s guide, How to Get Google Traffic to Your Substack Posts, pairs nicely with this file-name habit.
Alt Text That Feels Human And Ranks On Google
Alt text is the short description you add in Substack’s image settings. You click the image, open the little gear icon, and you will see a field for “Alt text.”
Alt text does two important jobs:
- It tells Google what the image shows.
- It helps readers using screen readers understand your post.
You do not need to write a novel. Aim for one simple sentence, under 125 characters. Use your keyword once if it fits, but write like a human, not a robot.
Bad alt text examples (too vague or stuffed):
- “image”
- “SEO SEO SEO Substack image SEO tips best Substack SEO”
- “photo of stuff on a desk”
Better alt text examples by niche:
- Writing tips: “Open notebook on a desk next to coffee for daily writing routine.”
- Solo business: “Simple Notion dashboard for one-person business planning.”
- Culture essay: “Crowded indie bookstore during a live author reading.”
- Tech / AI: “Chart comparing AI writing tools accuracy in 2025.”
Notice how each one:
- Describes the image in clear language.
- Hints at the topic of the article.
- Skips awkward keyword stuffing.
If your post targets “Substack image SEO,” you might write: “Screenshot of alt text settings used for Substack image SEO.” Natural, short, and clear.
For a wider checklist that covers titles, URLs, and more, Kristi Koeter’s Substack post optimization checklist for SEO is a helpful companion.
Placing And Resizing Images Inside Substack
Once your file names and alt text look good, the next step is where and how you use images inside the post.
Place images next to the right text
Google pays attention to the words around an image. That means:
- Put images close to the paragraph that explains them.
- Use related keywords in the nearby heading or sentence.
- Add a short caption when it adds clarity.
For example, if your post is about “newsletter welcome sequences,” place your screenshot of an email flow right after the paragraph that talks about that sequence. Then give it alt text like “welcome email sequence example for new Substack subscribers.”
Resize without breaking your layout
Substack already adjusts images for different screens, but you still control how big they feel inside the post. Large, heavy images can slow down the page and make the reading experience clunky.
Before you upload:
- Compress big images with a free tool like TinyPNG or JPEGmini.
- Aim to keep most images under 100 KB when possible.
After you upload:
- Use Substack’s drag handles to adjust size.
- Avoid stacking too many large images back to back.
If you want a quick visual guide to resizing, this tutorial shows the process step by step: A SUPER Easy Way to Resize Images in Your Substack Posts.
A simple rhythm works well: headline, short intro, first image, then body text. That first image can be a strong signal to both readers and search engines about what your post is really about.
How Image SEO Fits Into Your Bigger Substack Strategy
Substack has a strong domain, so Google already likes sending traffic to it. That means every small improvement you make, including image tweaks, can give you a noticeable lift.
When you pair:
- Clear titles and keywords,
- Helpful, focused content,
- Basic on-page SEO,
- And smart image habits,
you make it far easier for search engines to understand and feature your work.
If you want more guidance on tying all of this together, Karen Cherry’s guide, How to SEO for Substack, walks through practical steps without heavy jargon.
And if you batch your posts or schedule Notes ahead of time, you can treat image SEO as part of that same routine: rename, write alt text, place, publish.
Copy‑Paste Substack Image SEO Checklist
Use this mini checklist for every new post. Copy, paste, and keep it in your notes app or next to your editor.
Substack Image SEO Checklist
- Rename each image file with 3 to 5 clear words, using hyphens, no spaces.
- Include one main keyword in the file name when it makes sense.
- Upload the image, then add short, descriptive alt text in Substack’s image settings.
- Use natural language in alt text and avoid keyword stuffing.
- Place each image near the paragraph that explains or refers to it.
- Add a short caption if it helps readers understand the image.
- Compress large images before upload to keep pages loading fast.
- Use at least one strong image near the top of the post to anchor your topic.
- Before publishing, skim your post and confirm file names and alt text match the topic.
Conclusion: Tiny Image Tweaks, Big Search Wins
You do not need to turn into an SEO expert to get more search traffic. You just need a repeatable habit for how you name, describe, and place images in every Substack post.
Those habits send clear signals to Google, keep readers on the page longer, and quietly grow your reach over time. Substack image SEO is one of the easiest wins you can stack on top of the writing you already do.
Next time you sit down to publish, run through the checklist once. Make it part of your usual flow. Your future search traffic will thank you.
