It is a reasonable question to ask, and often one of the first an author reaches for, because a cover is visible and changeable in a way that reader demand or market size are not. That does not mean the cover is the actual weak point. A professional-looking cover on the wrong genre shelf can underperform, and a rougher cover in the right genre with strong reviews can still sell. The cover matters, but it is one part of a chain that includes discoverability, positioning and the product page as a whole.
This guide sets out how to check a cover properly, using genre comparison and a few structural checks, rather than a vague feeling that it "looks fine" or "looks amateur". It also explains what a cover cannot tell you on its own, and where to look if the checklist below does not turn up a clear problem.
What a cover can and cannot tell you
A cover’s job is to signal genre, tone and quality quickly enough that a browsing reader decides to look closer. It cannot, on its own, explain why sales have stalled, because a click on a product page depends on many things happening in sequence: whether the reader saw the book at all, whether the thumbnail caught their eye, whether the description then held their interest, and whether the price and reviews supported a decision to buy.
If a book is getting very few views in the first place, the cover is not yet the limiting factor, because too few people are reaching it to judge. If the book is getting reasonable views but a low click-through or a high bounce from the product page, the cover and the thumbnail are worth examining more closely.
Genre signalling
Readers browsing a category form snap judgements based on visual conventions: certain colours, fonts, imagery and layouts are strongly associated with particular genres, and readers use them, often unconsciously, to filter what is and is not "for them". A well-executed cover that ignores those conventions can look attractive in isolation and still fail to signal the right genre at a glance.
Example
Imagine a quiet, literary family drama given a bold, high-contrast cover with a shadowy figure and a jagged typeface more typical of psychological thrillers. Thriller readers might click, feel misled by the description, and leave a mixed review; the literary fiction readers who would have enjoyed the book may never notice it, because it does not look like the books they usually choose.
The most useful check here is a direct, honest comparison: place the cover next to five or six current, well-established books in the same category and ask whether it would sit comfortably among them, or whether it visibly reads as something else.
Thumbnail readability
Most readers encounter a cover first as a small thumbnail, in search results, a category listing or a recommendation carousel, often on a phone screen. A cover that works well as a full-size image can fail badly at thumbnail size if the title is in a delicate font, the imagery is busy, or the contrast between text and background is too low to read at a glance.
Thumbnail readability check
- Shrink the cover image to roughly the size it appears in search results and view it on a phone screen.
- Check whether the title and author name are legible without zooming in.
- Check whether the genre is still recognisable at that size, not just at full resolution.
- Check whether the central image or focal point is still distinguishable, not lost in detail.
Professional finish
Separate from genre fit, it is worth an honest look at finish: whether the typography is well-kerned and consistent, whether any imagery is well-integrated rather than obviously stretched or mismatched in resolution, and whether the overall composition looks intentional rather than assembled from disconnected elements. These are craft issues rather than taste issues, and they are usually visible once you know to look for them.
| Element | Worth checking |
|---|---|
| Typography | Consistent spacing, appropriate weight, no stretched or default fonts |
| Imagery | Matching resolution and lighting, no visibly stock or mismatched elements |
| Title hierarchy | Title, subtitle and author name sized to guide the eye in a sensible order |
| Print format | Spine and back cover text legible; bleed and trim correctly set for print, where relevant |
Series and brand consistency
For a series, or for an author building a recognisable body of work, consistency across covers helps readers who enjoyed one book recognise the next one quickly. An inconsistent style across a series can create confusion about whether books belong together, which matters more the further into a series a reader already is.
Reader expectation and description mismatch
A cover sets an expectation that the description and the book itself then need to meet. If the cover and description point to different things, for example a cover suggesting light romantic comedy alongside a description describing a dark psychological plot, readers who click may leave without buying, and those who do buy may leave a review reflecting that mismatch rather than the writing itself. Checking the cover and description together, as a single first impression, is more useful than assessing either in isolation. See our guide on whether the description could be the issue for the description side of this.
What not to assume
Do
- Compare the cover honestly against current, successful books in the same specific category.
- Check thumbnail size and legibility on an actual phone screen.
- Treat a cover change as one variable, tested and observed on its own where possible.
Avoid
- Assume low sales automatically mean a weak cover, without checking whether the book is being seen at all.
- Chase trends from unrelated genres just because they look striking.
- Change the cover, title, price and description all at once, since that makes it impossible to know what helped.
Cover diagnostic checklist
Private worksheet
Cover diagnostic checklist
Work through each item privately and honestly. Nothing here is scored, saved or sent anywhere; it is simply a structured way to look at the cover before deciding whether it is worth changing.
Your answers stay in this browser tab only. Nothing is scored, sent or saved to an account.
If the cover does look like a weak point
If several items above point in the same direction, particularly around genre signalling or thumbnail legibility, the cover is a reasonable next thing to address. That does not mean every earlier decision was wrong; genre conventions and reader expectations do shift over time, and a cover that worked well at launch can look dated or out of step a few years later.
If the cover appears to be one of the weak points, it is worth treating a redesign as a deliberate, single change: update it, then watch what happens over a reasonable period before also changing the description, price or keywords, so any effect can actually be attributed to the cover itself.
Common mistakes
- Judging the cover on taste rather than genre fit. A cover the author personally likes is not the same as a cover that reads correctly to genre readers browsing quickly.
- Never checking it at thumbnail size. Most first impressions happen small, often on a phone; a cover that only works full-size is not doing its job.
- Changing the cover and several other things at once. This makes it impossible to know afterwards whether the cover, the price, the description or something else made the difference.
- Assuming low sales alone prove the cover is the problem. Low traffic, weak metadata or an unclear description can produce the same symptom.
- Copying a trend from an unrelated genre. A striking design that belongs to a different genre can attract the wrong readers and confuse the right ones.
Frequently asked questions
How do I know if my cover is actually the problem?
Compare it honestly against current, successful books in the same specific category, and check it at thumbnail size. If it reads correctly for genre and is legible small, the cover is less likely to be the main issue, and it is worth checking [discoverability](/resources/book-sales-growth/why-is-nobody-finding-my-self-published-book) and the description instead.
Should I redesign my cover if sales are low?
Only if a genuine review, ideally compared against current genre covers, suggests it is a weak point. Redesigning without a specific reason removes a variable you could otherwise learn from.
Does a professional-looking cover guarantee sales?
No. A strong cover helps a book get a fair look, but reader interest, positioning, pricing and reviews all still play a part.
Can I test two covers against each other?
Some retailers and services offer limited testing options at the time of writing; check current retailer documentation for what is available, since features and rules change.
Does the print cover matter as much as the ebook cover?
Both matter for their own format. Print covers also need a correctly formatted spine and back cover, which ebook covers do not.