UX laws & heuristics
Fitts, Hick, Jakob, Miller, Doherty, Nielsen's 10 heuristics and dark-pattern detection — checked element by element.
Automated UX audit tool · 43 checks
Find the UX issues that are costing you conversions
Paste a URL. Lensux checks it against the laws of UX, WCAG accessibility and design psychology — and tells you which element breaks which rule, and how to fix it.
Or start a 3-day free trial — no card neededChecks are based on
- WCAG 2.2
- Nielsen's 10 heuristics
- Laws of UX research
- Dark-pattern research
Your free UX scan
Scanning…
0/100
- 0 passed
- 0 to review
- 0 issues
What to fix first
19 more checks in the full audit
- Fitts's Law tap targets on desktop and mobile
- WCAG contrast measured on the rendered page
- Typography, line length and layout shift
- AI design psychology and visitor simulation
- Continuous monitoring and PDF reports
3-day free trial · No credit card · Cancel anytime
Your site loses customers in places your analytics can't show
Conversions drop after a redesign
and nobody can say which change caused it.
Manual UX reviews take a full day
so they happen once — and never again.
Every deploy can break a fixed issue
and you only hear about it from a client.
Clients want proof, not opinions
before they approve the next change.
“When I hand over a website, I want proof that it follows proven UX rules — so I can defend every design decision and keep the client.”
From URL to a prioritised fix list in three steps
- Paste your URL
Desktop and mobile are audited together. No code, no plugin, no tracking script.
- Get a scored report
Every finding names the element, the rule it breaks, its severity and the fix.
- Fix it and stay covered
Monitoring re-checks your sites and flags anything that breaks again.
What you get: a report you can act on today
Nine audit engines in one dashboard
Color & contrast
WCAG contrast on the rendered page, palette balance, semantic colors and interaction states.
Accessibility
Alt text, heading order, ARIA misuse, duplicate IDs, skip links and reading level.
Typography
Font loading, scalable units, heading scale, line length and fallback fonts.
Layout & structure
Landmarks, DOM depth, breakpoints, z-index, layout shift and horizontal overflow.
Images & media
Modern formats, lazy loading, dimensions, SVG bloat, autoplay and captions.
Design psychology
First impressions, trust, visual hierarchy and persuasion, judged like a visitor would.
Design trends
Bento grids, spatial UI, micro-interactions and more, benchmarked against current sites.
AI visitor simulation
Describe a visitor. Lensux browses your page as that person and shows where they doubt or leave.
Continuous monitoring
Scheduled re-scans mark each issue as new, still open, fixed or back again — before your client notices.
A manual UX audit vs. Lensux
| Manual audit | Lensux | |
|---|---|---|
| Time per website | About a day of expert work | Minutes |
| Coverage | What one reviewer remembers | 43 checks, every time |
| Consistency | Varies between reviewers | Same rules, same scoring |
| Evidence | Screenshots and opinions | Element, rule, severity and fix |
| After launch | Rarely repeated | Scheduled monitoring |
| Cost | A consultant's day rate | From 9.95 € / month for 5 sites |
How designers, agencies and shops use Lensux
Freelance web designers
Run an audit before handover and attach the PDF report — the client sees measurable proof instead of “trust me”.
Agencies
Monitor every client site weekly. Regressions appear as “back again” before the client opens a ticket.
CRO specialists
Sort findings by severity, fix the high-impact ones first, then test the message with the AI visitor simulation.
Online shops
Find checkout buttons under 44 px and low-contrast prices on mobile — the small things that quietly cost sales.
Simple plans that grow with your client list
Start free. Upgrade only when Lensux has already found something worth fixing.
Free trial
0 € · 3 days
- 1 website
- Instant + full audit
- No monitoring
Pro
9.95 €/month
≈ 1.99 € per website
For solo designers
- 5 websites
- All audit engines
- Bring your own AI key
- No monitoring or PDF export
Premium
19.95 €/month
≈ 2.00 € per website
For growing studios
- 10 websites
- All audit engines
- Monitoring included
- PDF report export
- Bring your own AI key
Enterprise
59.95 €/month
≈ 3.00 € per website
For agencies
- 20 websites
- AI API key included
- Live monitoring
- PDF report export
Lifetime
399 € one-time
Founding-member access, forever
- 25 websites
- Monitoring + PDF reports
- Bring your own AI key
- Pay once — costs the same as 20 months of Premium
- 3-day free trial
- No credit card to start
- Cancel anytime
- Payments secured by Stripe
What's next for Lensux
- 1Beta and early testers
Closed access to shape the first audit models.
- 2Limited public opening
A small group of paying users outside the beta.
- 3Fixes and improvements
Beta feedback rolled into the scoring engine.
- 4Lifetime plan opens
A one-time plan to fund the next stage.
- 5New audit modules
More audit categories in the dashboard.
- 6Refinement pass
New modules tuned from real usage.
- 7Pricing update
Plans adjust to reflect the full feature set.
Built by a web designer who got tired of guessing
Most UX audits are either a long manual checklist or a vague AI opinion with nothing behind it. Lensux closes that gap: every finding names the rule behind it, the scoring is the same every time, and your sites are re-checked as they change.
I'm Javi Morales, a freelance web designer and CRO specialist based in Baden-Baden, Germany. I built Lensux to run the checks I used to do by hand — on every page, every time a site ships.
Javi MoralesFounder of Lensux
More about Javi Questions before you start
What is a UX audit?
A UX audit is a structured review of a website against proven usability rules — such as the laws of UX, Nielsen's heuristics and WCAG accessibility criteria — to find what makes visitors hesitate, struggle or leave. The result is a prioritised list of issues with the fix for each one.
Is the instant scan really free?
Yes. Paste any public URL and you get a UX score and the issues to fix first, without an account. We only keep the domain, the score and an anonymised rate-limit token — never the page content.
What does the full audit add to the free scan?
The free scan runs 24 checks on the page's HTML. The full audit runs all 43: it also opens your site in a real browser to measure tap targets (Fitts's Law), WCAG contrast, typography and layout shift, and adds AI design-psychology review, visitor simulation, heatmap prediction, monitoring and PDF reports.
Do I need a credit card for the trial?
No. The 3-day trial starts without a card. You only add payment details if you decide to keep a paid plan.
Which standards does Lensux check against?
WCAG 2.2 success criteria (including contrast, target size, bypass blocks and page language), Nielsen's 10 usability heuristics, the laws of UX (Fitts, Hick, Miller, Jakob, Doherty), Gestalt principles and documented dark patterns such as confirmshaming.
Does it work with WordPress, Shopify, Webflow or React sites?
Yes — Lensux audits any public URL, whatever it was built with. Sites that build their content with JavaScript are audited in a real browser in the full audit; the instant scan tells you when that applies.
Do I need my own AI key?
On Pro, Premium and Lifetime you connect your own key from OpenAI, Anthropic, Google Gemini or OpenRouter (including its free models). Enterprise includes the AI usage.
Can I cancel anytime?
Yes. There's no contract and no minimum term — you can cancel from your account settings.
Free guides to the rules behind every audit
Guide
How to do a UX audit (with a complete checklist)
Laws of UXFitts's Law: tap targets, distance and real examples
Laws of UXHick's Law: why more choices slow every decision
MethodHeuristic evaluation with Nielsen's 10 heuristics
Free toolWCAG color contrast checker
HubAll the laws of UX, explained for websites
Your next visitor is judging your site right now
See what they see — in seconds, for free.
Prefer to ask first?
Send a question and Javi answers personally, usually within one working day.