Private beta · Spring 2026 London · 2026

Know how
sustainable
your clothes
really are.

GreenStar is a browser extension that rates fashion products and brands as you shop online, so you can see how sustainable something actually is before you buy it, and find a better option if there is one.

Built by people who've worked at
Morgan Stanley S&P Global The University of Oxford LSE
The product

Open any
product page.
Get a rating.

Click once. GreenStar reads the product's materials, where it was made, care labels, and any sustainability claims, then combines all of that with the brand's track record. No sign-up, no interruption to your shopping.

100+
Retailers supported
100
Brands rated at launch
~15s
To rate a product
0
Accounts required
How it works

Three steps.
No homework.

Read the page, combine product details with brand performance, and point you somewhere better when it makes sense. See full detail →

01 · Read

We read
the page
for you.

The extension scans the product page and picks out what matters for sustainability. Brand, materials, where it was made, care labels, price, and any sustainability claims.

02 · Rate

Product plus
brand, in
one score.

60% what you're actually buying, 40% who made it. When key data is missing, we say so and lower the score accordingly. A transparent brand should never score the same as an opaque one.

03 · Redirect

A better
option, if
there is one.

Same style, similar colour, close to the price you were willing to pay, but with a meaningfully higher score. If nothing better exists, we'll tell you that too.

Why now

Transparency is
becoming law.

A once-in-a-generation wave of sustainability regulation is landing between 2026 and 2028. Brands that don't disclose will be forced to. Shoppers will have the right to ask. GreenStar is the layer that makes that data useful.

European Union Live · July 2026

Ecodesign for Sustainable Products Regulation.

The EU's ESPR entered into force in July 2024. From 19 July 2026, large fashion companies are prohibited from destroying unsold textiles, and must publicly disclose what they discard. Digital Product Passport rules follow in 2027.

Source: European Commission, Feb 2026 [1]
United States 2026 · 2027

California SB 253 & SB 261.

California's Climate Corporate Data Accountability Act requires 5,400+ companies with >$1B revenue doing business in the state to publicly disclose Scope 1 & 2 emissions from 10 August 2026, and Scope 3 from 2027.

Source: CARB, Feb 2026 [2]
EU-wide 2027

Digital Product Passports.

By July 2026, the EU will have a central DPP registry operational. The textile delegated act is expected late 2026 / early 2027, making DPPs mandatory for most apparel sold in the EU, with a compliance deadline around mid-2028.

Source: EU Green Forum, 2025 [3]

Full citations and links: greenstar.eco/references

The intention gap

Consumers say
one thing. They
do another.

It isn't an awareness problem. It's a friction problem. The gap between what shoppers believe and what they buy is where GreenStar lives.

59% of Gen Z admit their generation talks about sustainability more than they practise it. Source: RSM UK / Retail Economics, Dec 2025 [4]
20% of shoppers actively compare brands' sustainability credentials before buying. Source: Zalando Attitude–Behavior Gap Report [5]
33% of shoppers say sustainable options feel too expensive. Most never learn whether that's actually true. Source: Simon-Kucher Global Sustainability Study 2022 [6]
Methodology

An estimate.
Not an audit.

Every score is traceable. We show the signals we used, the signals we couldn't find, and exactly how missing data affected the result.

Read the methodology
0.6×
Product
+
0.4×
Brand
  • /01 Standards GOTS, OEKO-TEX, Bluesign, Fair Trade, REACH, ISO 14001, and more. 8 certs
  • /02 Incidents Severity and recency of publicly reported ESG incidents since 2020. 5yr window
  • /03 Emissions Decarbonisation rate vs. the 1.5°C sector pathway (6.1% per year). SBTi-linked
  • /04 + 4 more Climate Targets, Suppliers, Water, Transparency. View all →
For brands · Dashboard

Benchmark any
brand. Live.

The same data powering the consumer extension, in a dashboard built for fashion teams. Compare as many brands as you want, drill into any component, see your own products alongside your competitors'. Try the demo →

A
Arket
Stockholm, SE
3.4
H
H&M
Stockholm, SE
3.0
Insight Arket is 13% more sustainable than H&M overall, led by Incidents (+1.3) and Transparency (+0.5).
Alternatives

A better option.
Same style.

Information alone doesn't change what people buy. Every low score is paired with something you could actually wear instead. Same style, similar colour, within 20% of your price, and a genuinely better score.

YOU ARE VIEWING Heavyweight Basic Hoodie Retailer X · Cotton blend
£32.99 3.2/5
ALTERNATIVE Hemp Oversized Hoodie Pangaia · Hemp / Recycled
£35.00 4.1/5
Why we built it

Most shoppers don't want to read a 40-page ESG report. They just want to know: is this sustainable, or not? And if not, what should I buy instead?

Why us

Three things
nobody else has yet.

Sustainability ratings aren't new. What's new is where the rating lives, how it's calibrated, and what gets learned from every click. This is the defensible core.

01.

Distribution at
the point of sale.

Existing ratings live in blogs, apps, and PDFs. GreenStar lives on the product page itself, the only place purchase decisions actually happen. Every installed extension is distribution a competitor doesn't have.

02.

A behavioural
data flywheel.

Every rating served is paired with anonymised behavioural data: price sensitivity to sustainability, which components drive switching, which alternatives convert. The dataset compounds. No LCA database has this.

03.

A calibrated
methodology.

The 7-component framework and the 60/40 product-brand split were designed by a former commodity ESG ratings analyst at S&P Global. It's opinionated, defensible, and built to survive regulatory scrutiny.

The sustainability data exists. The rating frameworks exist. What's missing is a layer that puts both in front of consumers at the moment they're actually deciding. That's what makes GreenStar interesting.

Kayyan Elmasry, Founder
Formerly Morgan Stanley · Fixed Income ESG Strategy & Research
Private beta

Be first to shop
with the signal on.

Limited seats. Early users help shape the methodology, the UI, and which retailers we support first. We only email when your invite is ready.

Chrome & Safari · UK first