Buttercup
The Password Manager You Deserve.
FactScore™ 0
OnlyKey
OnlyKey is an open source alternative to YubiKey
Updated February 2026
| Buttercup | OnlyKey | |
|---|---|---|
| Rating | N/A | 5.0★ |
| Reviews | 0 | 1 |
| Pros | 0 | 0 |
| FactScore™ | 0 | 15.1 |
FactScore™ Comparison
FactScore™ weighs both quality (rating) and popularity (reviews) for a fairer ranking than stars alone.
Pros & Cons
Only in Buttercup — Pros
No unique pros listedBoth tools — Pros
—Only in OnlyKey — Pros
No unique pros listedOnly in Buttercup — Cons
—Both tools — Cons
—Only in OnlyKey — Cons
—Details
| Buttercup | OnlyKey | |
|---|---|---|
| Categories | Password managers | Password managers |
| Platforms | Web · iOS | Web |
| Became Popular | May 23, 2017 | December 25, 2019 |
| Website | buttercup.pw | onlykey.io |
Who Should Pick Which?
Choose Buttercup if...
- No unique pros listed
Choose OnlyKey if...
- No unique pros listed
With a FactScore™ of 0 vs 15.1, OnlyKey leads in community reception. Buttercup uniquely offers No unique pros listed, while OnlyKey stands out for No unique pros listed.
What Users Say
Buttercup
No reviews yet
OnlyKey
Using my OnlyKey-Duo for half a year now , I am enthousiastic about it. Functioning reliable on my USB A/C devices. Easy configuration and backup , but lacks support if you have issues. (just forum...
Related Comparisons
Frequently Asked Questions
Which is better, Buttercup or OnlyKey?
Based on FactScore™, OnlyKey leads with a score of 15.1 vs 0. OnlyKey has a higher rating of 5.0★ compared to N/A★.
What are the pros of Buttercup compared to OnlyKey?
Buttercup uniquely offers: No unique pros listed.
What are the pros of OnlyKey compared to Buttercup?
OnlyKey uniquely offers: No unique pros listed.
Is Buttercup better rated than OnlyKey?
Buttercup is rated N/A★ from 0 reviews. OnlyKey is rated 5.0★ from 1 reviews.
What is the FactScore™ of Buttercup and OnlyKey?
FactScore™ weighs rating and review volume together. Buttercup scores 0 and OnlyKey scores 15.1.
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