LoupeKit Review (2026): Pricing, Features & Honest Verdict

TLDR

LoupeKit is a browser extension that reads any page like you built it: it names the tech stack, extracts the palette and box model, runs SEO and accessibility checks, and scores how much of the page looks AI-generated. It does it all locally, cheaply, and in one place. Best for: developers, designers and SEOs who inspect web pages. Price: Free plan, EUR 6.99/mo. Rating: 7.1/10.

What is LoupeKit?

LoupeKit is a browser inspector that tells you how any page you have open was built. Open the floating panel and it names the frameworks and technologies behind the site, pulls out the colour palette, fonts and assets, measures the box model of any element you hover, and runs SEO and accessibility checks. It also does something most inspectors do not: it scores how much of the page reads as raw AI output. The tagline sums it up, read any page like you built it, and that is a fair description of the experience.

Under the hood it packs 75 tools across nine tabs, Stack, Vibe, UI, Developer, SEO, Accessibility, Domain, Server and Tools, with a command palette on Cmd+K or Ctrl+K to jump between more than 200 functions. It works in Chrome, Edge and Chromium browsers, plus Firefox from version 140. The site credits apptiary.com for its build tooling. It matters now because two jobs that used to need separate tools, figuring out a competitor’s stack and judging whether content is AI-written, are increasingly done by the same people, and LoupeKit puts both in one panel. The privacy angle is central: it reads the page locally and does not request permission to access all sites.

What Are LoupeKit’s Key Features?

Stack detection with evidence

The Stack tab identifies the technologies a site uses and, importantly, shows the evidence and a confidence level for each finding. That is a step up from tools that just print a logo list, because you can see why it thinks a site runs a given framework. For competitive research or debugging, knowing the reasoning matters as much as the answer. It is the feature most people will open LoupeKit for first.

Vibe score for AI content

The Vibe tab scores how AI-generated a page looks, 0 to 100, across five weighted categories, markup, CSS, runtime, copy and accessibility, using 66 heuristics. Each finding says exactly what it measured and what to change, and clicking one scrolls the page to that element. It is a genuinely novel feature. The honest caveat is that it is a heuristic estimate, not proof; treat it as a signal, not a verdict, and it is useful.

UI inspector

Hover any element and the UI tab shows its box model, typography and colours. It is the design-inspection job you would otherwise do in devtools or a separate extension like CSS Peeper, folded into the same panel. For designers reverse-engineering a layout or lifting a colour, it removes a couple of steps. Nothing revolutionary, but it is polished and fast.

SEO and accessibility audits

The SEO and Accessibility tabs give you a crawler’s-eye view of the page, contrast checking, and an accessibility-tree analysis. These overlap with dedicated auditors, but having them a click away while you are already inspecting a page is convenient. Combined with the scored findings elsewhere, LoupeKit works as a quick first-pass audit before you reach for a heavier specialist tool. The crawler’s view in particular is handy for spotting the gap between what a browser renders and what a search engine actually sees, which is where a surprising number of SEO problems hide.

Command palette and 75 tools

The whole thing is tied together with a command palette on Cmd+K or Ctrl+K that searches across more than 200 functions, so you are not hunting through nine tabs to find the one measurement you want. With 75 tools on offer, discoverability could easily have been a mess; the palette is what keeps LoupeKit fast to use rather than overwhelming. It is the difference between a bloated toolbox and one you actually reach for, and it is a big part of why the breadth feels like a feature instead of clutter.

How Much Does LoupeKit Cost?

LoupeKit starts free. The free plan is free forever and includes stack detection and the core inspection tools, but it caps you at 3 vibe audits. To lift that and unlock unlimited audits and reports across all the tools, the Monthly plan is EUR 6.99 per month. There is also a Lifetime licence at EUR 74.99 one-time, which the site says is rising to EUR 119.99, so the current price is an early-adopter rate.

That is cheap for what you get. Compare the pieces: Wappalyzer’s browser extension is free but its paid API and lead plans run far higher, dedicated AI-content detectors like Originality.ai start around $15/mo, and design inspectors are often free but single-purpose. LoupeKit bundles all of those jobs for under EUR 7 a month, or roughly the price of two coffees once for the lifetime deal. If you would otherwise pay for even one specialist tool, LoupeKit’s economics are hard to argue with.

The honest note on cost: the lifetime price rising over time is a mild pressure tactic, but at EUR 74.99 it is still a fair deal for a tool you would use weekly. The free plan is genuinely usable for occasional checks.

Who is LoupeKit Best For?

Use LoupeKit if you regularly poke at web pages: developers checking how a competitor built something, designers lifting palettes and layouts, SEOs auditing markup, or freelancers who do all three in a day. If your work involves opening a site and asking how it was made, LoupeKit collapses several tabs of tooling into one panel, and the local-first design means you can run it on client sites without privacy worry.

Skip LoupeKit if you need best-in-class depth in a single area. A dedicated SEO suite will out-audit its SEO tab, a specialist AI detector will be more defensible than the vibe score, and full devtools go deeper than the UI inspector. Skip it too if you only inspect a page once in a blue moon, because the free plan already covers that and you will not need the paid tiers.

Best LoupeKit Alternatives

Wappalyzer

Wappalyzer is the best-known tech-stack detector, with a free browser extension and paid API and lead-generation plans that get expensive fast. It goes deeper on technology identification and maintains a huge, well-known dataset. What it does not do is design inspection, accessibility audits or AI-content scoring. Choose Wappalyzer if stack detection is all you need and you want the most trusted source; choose LoupeKit if you want that plus the rest in one panel.

CSS Peeper

CSS Peeper is a free browser extension focused on design inspection: colours, fonts, assets and the box model, presented cleanly. It is lighter and more focused than LoupeKit’s UI tab and is a favourite among designers. It does no tech detection, SEO or AI scoring. Pick CSS Peeper if design inspection is the only job you care about and you want it free; pick LoupeKit if you want inspection alongside everything else.

Originality.ai

Originality.ai is a dedicated AI-content detector aimed at editors and SEO teams, with paid plans from around $15/mo. It is more rigorous and more defensible than LoupeKit’s vibe score, and it is built specifically to judge whether text is AI-written. It does nothing about tech stacks or design. Choose Originality.ai if AI detection is a serious, standalone need; choose LoupeKit if the vibe score is one signal among many you want in a cheaper, broader tool.

Final Verdict: Is LoupeKit Worth It?

LoupeKit is a well-built Swiss Army knife for anyone who inspects web pages. Tech detection with evidence, a fast UI inspector, SEO and accessibility checks, and a genuinely novel AI-content score, all running locally with no host permissions, add up to a tool that respects both your workflow and your privacy. At EUR 6.99 a month or a EUR 74.99 lifetime licence, it is priced to be an easy yes for the people who will use it often.

It sits at 7.1 because breadth is also its ceiling. Each tab is good, but each is beaten by a dedicated specialist, and the headline vibe score is a heuristic you should not over-trust. That is the nature of an all-in-one: convenience over depth. If you reverse-engineer sites, audit your own pages, or want a quick read on how AI-written something looks, LoupeKit is well worth the small price and an easy recommendation. If you need forensic depth in one area, keep your specialist tool and treat LoupeKit as the fast first look.