Comparison

Roomster vs Karbon

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Roomster

Find a room to rent or a compatible roommate globally. Connect with verified individuals and browse thousands of listings with photos and detailed descriptions. Securely message potential matches and receive real-time alerts for new opportunities.

Highlights
  • Browse rooms and apartments for rent
  • Connect with validated roommates
  • Global listings in 18 languages
  • Private in-app messaging
  • Easy profile setup with social validation
  • Real-time alerts
Features
Read full description

Easily find a room to rent or a compatible roommate—anywhere in the world. Roomster connects you with validated renters and roommates in over 192 countries. Whether you're relocating nearby or abroad, Roomster helps you find safe, affordable housing and people you can trust. Key Features: Browse Rooms & Apartments for Rent Discover thousands of listings with photos, pricing, and detailed descriptions. Connect with Validated Roommates Match with roommates whose lifestyle, interests, and habits align with yours. Global Listings in 18 Languages Search rooms and roommates in cities across the globe. Private In-App Messaging Chat securely without giving out your personal contact info. Easy Profile Setup with Social Validation Add photos, interests, and social media links to make your profile stand out and validated. Real-Time Alerts Get notified instantly about new messages, likes, and room listings that match your preferences. Why Roomster? Trusted since 2003, Roomster has helped over 10 million people find roommates and rooms for rent. From students to professionals, Roomster is the go-to app for finding flexible, safe, and affordable living options. Download Roomster today and make your next move easier—whether you're searching for a room, a roommate, or both. Consult our Privacy Policy at https://www.roomster.com/privacy And our Terms of Use at https://www.roomster.com/terms We are always working hard on improvements to make finding your next home even easier. Please continue to send your feedback to iosfeedback@roomster.com. We appreciate it!

About

Karbon

This app allows environmentally conscious individuals and businesses to support clean energy and eco-friendly initiatives. Users can contribute to projects like tree planting and ocean de-acidification, track their impact, and receive achievement badges. Offset plans can be switched or canceled, with payments charged monthly or annually.

Highlights
  • Support tree planting and carbon reduction projects
  • Receive achievement badges
  • Switch supported projects
  • Attend eco-friendly events
  • Calculate carbon footprint
  • Monthly and annual offset plans
Features
Read full description

Karbon-X is an app that caters to environmentally conscious people and businesses who wish to contribute to clean energy and eco-friendly initiatives and offset their carbon emissions. The app is free to download. What can users do? *Support projects from tree planting to carbon reduction projects such as ocean de-acidification *Receive achievement badges as a way of appreciation for supporting a project *Switch projects that you support with no changes to your Offset plan *Attend events *Corporations and individuals can support any carbon-reducing project Offset Plans & Terms With Karbon-X, users can support a range of verified projects to promote sustainability and reduce carbon footprints. Karbon-X provides a pre-determined carbon footprint calculation based on your situation and needs. The user selects an offset plan to fund an on-the-ground carbon reduction project. As a show of appreciation, a badge is given to the user. Badges are not purchased in the app. Payment is charged every month or annually and can be canceled anytime through the Web app or mobile apps. Refunds are not provided once payment has been made. Plans do not increase based on your selected project unless you change your plan to include more plan members. For more info please visit our Terms of Service https://karbon-x.com/termsofservice/ or Privacy Policy https://karbon-x.com/privacy/

Screenshots

Roomster4 screens
Karbon4 screens

Verdict

The call

The clearest difference is review sentiment: Karbon at 78% against Roomster's 22%. Karbon also leads on rating (4.7 vs 4.0) and in-app purchases (none vs 10). Roomster's advantage is ratings volume (22K vs 15) and update cadence (every 3 days vs every 2 weeks). On price and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Roomster sells 9 in-app purchases, starting at $9.99 per 7 days. Karbon asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Karbon holds the better App Store score, 4.7 against 4.0. That said, the two scores are not equally well evidenced: Roomster has 22K ratings behind it against 15, so its average is the more settled of the two. Written reviews point the same way: 22% of Roomster's written reviews are positive against 78% of Karbon's.

UpkeepUpdate frequency

Roomster ships an update every 3 days, Karbon every 2 weeks. The most recent releases landed on November 7, 2026 and November 3, 2026 respectively.

Scorecard9 real differences · 2 level
Roomster versus Karbon: the parameters behind the verdict, then further details
ParameterRoomsterKarbon
PriceFreeFree
Rating4.0 (22K ratings)4.7 (15 ratings) — better
Positive reviews22.1% of reviews77.8% of reviews — better
Number of ratings22K — better15
Update frequencyEvery 3 days — betterEvery 2 weeks
AdsYesNo — better
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
Best chart rank#72 — better—
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS16.013.0 — better
Further details — not scored
Size99 MB91 MB
Age rating17+9+
DeveloperRoomster Corp.Karbon-X Project Inc.

Customer experience

Roomster

All ratings21,892 ratings
Positive72.8%
Neutral4.3%
Negative22.8%
Written reviews1,380 reviews
Positive22.1%
Neutral2.6%
Negative75.3%

Karbon

All ratings15 ratings
Positive93.3%
Neutral0.0%
Negative6.7%
Written reviews9 reviews
Positive77.8%
Neutral0.0%
Negative22.2%

Bugs and requests

Roomster

Reported bugs

4 issues
  • Login issues
  • Frequent crashes
  • Listings not updating
  • Verification problems

Requested features

4 requests
  • Better search filters
  • Ability to delete account
  • More transparent pricing
  • Improved user experience

Karbon

Not enough reviews yet to summarise bugs or requests.

In-app purchases

9 purchases

Roomster

Subscriptions5
  • Full access$9.997 Days
  • Full access$11.997 Days
  • Full access$19.991 Month
Show 2 more
  • Full access$29.991 Month
  • Full access$49.992 Months
One-time4
  • Id Verification$2.99
  • Id Verification$5.99
  • Background Check2 variants$9.99
Show 1 more
  • Id Verification$14.99
None

Karbon

No in-app purchases

Questions

Is Roomster free?
Roomster is free to download, with in-app purchases available.
Is Karbon free?
Karbon is free to download, with no in-app purchases.
Which has better reviews, Roomster or Karbon?
Karbon is rated higher. Roomster averages 4.0 out of 5 from 22K ratings, while Karbon averages 4.7 from 15 ratings.
Do Roomster or Karbon have ads?
Roomster shows ads; Karbon does not.
Which is updated more often, Roomster or Karbon?
Roomster ships an update every 3 days, and Karbon every 2 weeks. Most recently, Roomster was updated on November 7, 2026 and Karbon on November 3, 2026.

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