How it works
Eight layers, working together.
Purus is an iOS browser that filters on your device. Here is what each layer does, what the on-device AI adds, what leaves your phone, and where Purus's limits are.
Eight layers
Every page. Every search. Every time.
Block List
Every request is checked against thousands of known explicit domains and ad networks before anything loads.
DNS Filtering
All domain lookups route through AdGuard Family Protection, which blocks 93.8% of explicit domains at the network level according to AdGuard's own published data.
Keyword Filter
Every search query typed anywhere in the browser is scanned against 507 blocked keyword patterns.
URL Inspector
Every navigation is checked for known bad domains, suspicious paths, and redirect chains.
Cosmetic Filtering
CSS-level rules hide explicit images, banners, and embedded elements that pass the domain block list — so even a clean-looking URL can't surface unwanted content.
Safe Search Enforcement
Safe Search is enforced at the URL level across Google, DuckDuckGo, Bing, Yahoo, and Startpage. Every other search engine is protected through DNS-level domain blocking and keyword filtering applied to every search query.
YouTube Restricted Mode
Every YouTube request is rewritten to force Restricted Mode, filtering adult-flagged videos from all feeds, search results, and recommendations.
Platform-Specific Filtering
Reddit is restricted to safe communities, Facebook search queries are filtered against the same keyword patterns used across all supported platforms, and Amazon search results exclude adult product categories before the page renders.
Why it's different
Stacked, and nothing to switch off.
Purus runs eight independent filtering layers at once. Most competitors don't run more than two or three.* And inside the app there's no toggle for any of them, so there is nothing to switch off in a weak moment.
* Based on number of simultaneous filtering layers compared to publicly available consumer browser filters.
PurusAI
A smarter layer of protection.
An on-device layer that checks images as they render. It's included in every Purus plan, alongside the eight layers above.
Real-Time Detection
Scans images as they render, catching explicit content before it ever appears on screen — not after you've already seen it.
100% On-Device
Every scan runs locally using a downloaded image classification model. No image, screenshot, or browsing data ever leaves your phone.
Catches What Filters Miss
Goes beyond domain and keyword blocking to catch embedded images, social feeds, cached content, and anything arriving through a clean-looking URL.
Always On
No manual scans, no schedules to manage. Protection runs continuously in the background the moment it's enabled.
Platform Coverage
Social Media, Done Right
Active filtering
YouTube
Restricted Mode enforced, safe search locked, explicit searches blocked
Explicit searches blocked
Safe search enforced, NSFW communities blocked
Blocked entirely
TikTok
X
Snapchat
Tumblr
Users who navigate to these platforms will see a Purus block page explaining why.
Keyword search filtering applies to all supported platforms — the same 507 patterns that catch explicit searches on Google also apply to Facebook, YouTube, and Reddit.
Safe search enforced everywhere you browse
Purus doesn't just suggest safe search — it's enforced automatically across every engine you use, whether through direct safe-search enforcement or DNS and keyword-level protection.
All third-party trademarks and logos are property of their respective owners. Purus is not affiliated with or endorsed by any of these companies.
Privacy
What stays on your phone, and what doesn't.
Content filtering decisions — block lists, keywords, content rules, and PurusAI's image checks — happen on your device. Your history, bookmarks, and tabs stay on your phone, and there is no account.
A few things do leave your device, in limited ways: Purus fetches updated block lists; if you turn on DNS protection, domain lookups go through AdGuard's family filter; if you tap “Report it” on a blocked page, that one URL is submitted to us; and if you enable Search Suggestions, partial search text goes to your chosen search engine. The Purus app doesn't use third-party analytics SDKs.
Full detail is in the Privacy Policy.
Honest limits
What Purus doesn't do.
- No filter is perfect. Purus significantly reduces exposure to explicit content but cannot guarantee complete filtering of all online content.
- Purus's eight layers run inside Purus. Apple doesn't allow any app to control what happens inside another app, so Purus can't filter content inside other apps. DNS protection, once on, blocks explicit domains at the network level for other browsers too.
- To limit other browsers or apps, pair Purus with iOS Screen Time.
Setup
Ready in a couple of minutes.
Download Purus
Start your 14-day free trial on the App Store. No account.
Turn on DNS protection
In Settings: General → VPN & Device Management → DNS → enable “Purus DNS Filter”. Purus walks you through it on first launch.
Make Purus your default browser
In Settings, tap Default Browser App and select Purus, so links from Mail and Messages open with protection on.