01Mistakes that cost visitors immediately
Visitors decide quickly. Nielsen Norman Group's analysis of dwell times found the first 10 seconds of a visit are when people are most likely to leave, in its research on how long users stay on web pages. These mistakes lose people in those seconds.
| Mistake | Why it hurts | Fix |
|---|---|---|
| Vague headline ("Welcome", "Innovation for tomorrow") | Visitors cannot tell what you do | Say what you do and for whom in under 10 words |
| No clear next step | Interested visitors do not know where to go | One primary button, visible on the first screen |
| Slow first load | People leave before seeing anything | Compress images, remove unused scripts |
| Broken mobile layout | Most visitors are on phones | Design and test mobile first |
02Mistakes that make a site look amateur
- 1Too many fontsThree or more typefaces fight each other. Use one or two; best fonts for websites has safe pairs.
- 2Too many text sizesNine slightly different sizes read as noise. Pick four or five from a scale.
- 3Random spacingGaps of 13, 22 and 37 pixels look accidental. Use a fixed scale, such as multiples of 8.
- 4Competing colorsSeveral bright colors leave nothing to draw the eye. Neutrals plus one accent; see how many colors should a website have?.
- 5Generic stock photosHandshakes and people at laptops signal template. Use your real product, team and work.
- 6Everything centered and equalWhen every element has the same weight, nothing stands out. Give each section one focal point.
03Mistakes that hurt readability and accessibility
Light gray text on white looks elegant in a mockup and fails real people. The Web Content Accessibility Guidelines require a contrast ratio of at least 4.5:1 for normal text, according to the W3C's contrast guidance. Tiny body text, long lines that run across a wide screen and walls of unbroken text add to the problem.
- Body text under 16 pixels on mobile.
- Lines longer than roughly 75 characters, which make the eye lose its place.
- Text over busy images without a background or overlay.
- Links that look identical to plain text.
- Animations that cannot be turned off; are website animations good? covers when motion helps.
04Mistakes in structure and content
Some design problems are really content problems. A navigation menu with 12 items, a homepage that tries to describe every service, and three different calls to action on one screen all come from not deciding what matters most. Decide the one thing each page should achieve, then remove what does not serve it.
Placeholder text left in, outdated copyright years and dead links also undermine trust quickly. If you are building with AI, check that every generated sentence is true and specific to you. How to make a website not look AI-generated covers the giveaways.
05How to audit your own site in 20 minutes
- 1Five-second testShow the homepage to someone for five seconds. Ask what you do and what they would click.
- 2Count fonts and colorsOpen your browser's developer tools or simply list them. More than two fonts or one accent color is a flag.
- 3Phone checkOpen every page on your own phone, in daylight, with one hand.
- 4Speed checkRun Google's PageSpeed Insights and fix the largest image first.
- 5Contrast checkTest body text and buttons against their backgrounds.
- 6Read every wordRemove anything vague, untrue or there only to fill space.
What people who tried it say
Hacker News threads about website design often criticize the same things this list does: slow pages, heavy animations, low contrast and generic templates. A recurring point is that plain, fast and clear beats elaborate and slow.
- Why does every website landing page look like this now?Hacker News
Commenters debate the standard landing page template, with criticism of oversized heroes, vague slogans and stock illustrations that say little about the product.
- Why do all websites look the same?Hacker News
Discussion of why sites converge on the same patterns, with commenters noting that familiar structure helps users while generic visuals make sites forgettable.
Looking for more first-hand opinions? Search Reddit for “common website design mistakes”. We link the live threads rather than summarizing them, so you read them in full.
Our take
fix the headline and the contrast before anything else. Those two cost more visitors than every other mistake on this list combined, and both take minutes to fix.
Where this falls short
Some of these are guidelines rather than laws; distinctive brands break rules deliberately and well. Accessibility thresholds are legal requirements in some contexts and best practice in others, depending on where you operate.
Orlume avoids most of these by design: it settles hierarchy, type scale, palette and spacing before generating code, so a site starts with two fonts, one accent and a consistent rhythm instead of accumulating them by accident.
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Sources
- 1.How long do users stay on web pages? · Nielsen Norman Group
- 2.Understanding Success Criterion 1.4.3: Contrast (Minimum) · W3C
- 3.PageSpeed Insights · Google
Researched and written by the Orlume team · Updated October 2026
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