All three let the worst ingredient drive the verdict, in three different ways, and only Yuka takes no brand money: Think Dirty listed a $322 per product review fee for brands, EWG charges $750 per formulation for its VERIFIED mark.
SlipperSkin finding
Read on 23 October 2026, Think Dirty's lifetime plan cost $199.00 in the US App Store against $99.00 on its own website when we read that on 21 October 2026: 2.0 times as much, and $100.00 more, for the same "Clean Beauty Boss" lifetime tier.
Each is better at one thing:
By three different rules, all published. Yuka sorts ingredients into four tiers and lets the riskiest set the band: "between 0 and 24/100 if a high-risk ingredient (red) is present", 0 to 49 for orange, and never below 50 if only green and yellow ingredients remain. Every other at-risk ingredient then costs points, from 2 to 12. Think Dirty, as its methodology read on 21 October 2026, rates a product by default "no lower than the highest rating of any individual ingredient", gives 10 when several ingredients rate high, and assigns 7 or higher to any product listing "fragrance". EWG works per hazard category: it adds "the highest scoring ingredient to the average score for the rest", weights and sums the categories, then scales everything from 1 to 10, with the top 5% most hazardous given a 10.
On real products this is why the three often disagree, and why our 20-product study found databases splitting on most best sellers. EWG's own worked example is coal tar, water and sodium chlorite: 100 plus the average of 0 and 30, a raw cancer score of 115.
Readers pay all three; brands pay two. Yuka publishes its 2025 revenue on its independence page: $11,884,771 from Premium subscriptions, and states brands cannot pay it to advertise. Think Dirty's partner pricing page listed a non-refundable review fee of $322 per SKU, then "monthly licensing fees" for verified partners, whose benefits include "Pinned Results" and "First Scroll Priority" (all read 21 October 2026). EWG charges a $750 per formulation evaluation fee plus an annual licence for EWG VERIFIED, and its FAQ says VERIFIED products are listed first in search results; half its revenue is individual donations.
| App | From or to | What the page says |
|---|---|---|
| Yuka | Readers | Premium $10 to $20; $11.9M in 2025 |
| Yuka | Brands: none | "Brands cannot pay Yuka to advertise" |
| Think Dirty | Readers | lifetime $99 web, $199 iOS; $39.99/yr web (read 21 October 2026) |
| Think Dirty | Brands | $322 per SKU, monthly licence, pinned spots (read 21 October 2026) |
| Think Dirty | Affiliates | 6% on Premium sales (read 21 October 2026) |
| EWG | Individual donors | one-half of 2024 revenue |
| EWG | Foundations | about one-third of funding |
| EWG | Brands | $750 per formulation, licence; listed first |
| EWG | Amazon | "a nominal percentage" of sales |
| EWG | App users | Premium $19.99 in the App Store |
All three scan free; the paid tiers differ by where you buy. Yuka's App Store listing offers "Premium Member" at $10, $15 or $20 with the same features at every price, and its web page prices it at $15 a year. EWG's listing shows "Premium $19.99" without a period, while EWG says the core features "will always be free". Think Dirty is the one where the shop matters: its website offered All Access at $39.99 a year (reduced from $59.99) and lifetime for $99 when we read it on 21 October 2026; the App Store lists lifetime at $199.00. On the web prices, lifetime overtakes yearly in year 3.
Yuka declares the least and Think Dirty the most. On the US App Store, Think Dirty declares 7 types of data that may be used to track you across other companies' apps and sites, EWG's Healthy Living 2, and Yuka none.
| App | Data used to track you | Data linked to you |
|---|---|---|
| Yuka | none declared | Usage Data, Diagnostics |
| Think Dirty | 7: Purchases, Location, Contact Info, Search History, Identifiers, Usage Data, Diagnostics | the seven tracked types, User Content |
| EWG Healthy Living | 2: Location, Identifiers | Location, Contact Info, Identifiers |
Yuka red (0 to 24): at least one ingredient is rated high risk. Tap it; that one set the band. Think Dirty 7+: either one ingredient rates 7 or more, or the label says "fragrance". EWG 3 to 6: moderate hazard on EWG's evidence, not exposure. Check the "data" rating too. All three: none weighs how much is in the bottle. If they disagree, compare the ingredient lists.
We read Yuka's scoring and independence pages, EWG's Skin Deep method, FAQ, VERIFIED portal and funding page, and all three US App Store listings on 23 October 2026. Think Dirty's website refused automated reading on 23 October 2026, so its methodology, partner, pricing and price pages are as read on 21 October 2026 and dated that way here. Figure 1 applies each published rule to an invented ingredient list; it is an illustration, not a score any app gave. SlipperSkin reports what each app says and does not give its own safety verdict on any ingredient.
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For a quick verdict from an app no brand can pay, Yuka; for fragrance, Think Dirty, which rates any product listing "fragrance" 7 or worse. Both let the riskiest ingredient set the score, and neither weighs how much of it is in the product.
Because at least one ingredient is rated high risk. Yuka's published rule holds the score between 0 and 24 out of 100 when a red ingredient is present, however good the rest of the list is.
EWG says brands never influence its scores. Brands do pay for the EWG VERIFIED mark: a $750 per formulation evaluation fee plus an annual licence, read 23 October 2026, and VERIFIED products are listed first in Skin Deep search results.
Yes. When we read its partner pages on 21 October 2026, Think Dirty listed a non-refundable $322 per SKU review fee, then monthly licensing for Verified Brand Partners, whose benefits include pinned results; it says brands cannot pay to improve ratings with false information.
It was: on 21 October 2026 its site offered lifetime access for $99.00 and a year for $39.99, while the US App Store listed lifetime at $199.00 on 23 October 2026.
No. EWG says its hazard rating does not account for exposure or individual susceptibility, which it calls the factors that drive health risks. It rates the hazard of the ingredients, not the dose in the product.
Yuka, Think Dirty and EWG all let the worst ingredient drive the verdict, by three different published rules, and none weighs dose. Yuka takes no brand money; Think Dirty and EWG sell brands verification and position. Pick the rule that matches your worry, and if you buy Think Dirty, buy it on the web.