Crates / Compare / ring vs rsa
Rust crates side by side · data Oct 24, 2026
ring vs rsa
Short answerBy steady daily use, ring is bigger: 2,112,308 real downloads a day against 717,631 for rsa (2.9x). 1,837 crates depend on ring and 1,182 on rsa. ring last shipped 19 months ago, rsa 18 days ago.
ring
Widely usedWidely used and steady.
1,837 crates depend on it; no release in the last 90 days, so its count is all steady use.
An experiment.
rsa
Widely usedWidely used and steady.
1,182 crates depend on it; downloads jump on release days (1.4x the baseline).
Pure Rust RSA implementation
ringrsa · 100% = that crate's normal quiet day, so a spike to 300% is triple its usual traffic
Every number, side by side
| Same window, same method | ring | rsa |
|---|---|---|
| Real downloads a day | 2,112,308 | 717,631 |
| Crates that depend on it | 1,837 | 1,182 |
| Last release | 0.17.14, 19 months ago | 0.10.0-rc.19, 18 days ago |
| Trend vs the field | -2% | -4% |
| Release-window share | 0.0% | 3.0% |
| Downloads in the window | 194,741,593 | 63,841,064 |
| All-time downloads | 833,501,264 | 252,034,231 |
| Versions published | 133 | 65 |
| License | Apache-2.0 AND ISC | MIT OR Apache-2.0 |
| MSRV | 1.66.0 | 1.85 |
| First published | Aug 15, 2016 | Jul 24, 2018 |
Which to pick
- Downloads tell you what is common, not what fits. Each crate's own description above says what it is for; when the jobs differ, pick by the job.
- When both fit, prefer the one more crates depend on (ring, 1,837 dependents): more eyes, more answered questions, and you may already have it in your tree.
- Check the release dates against your own pace: ring 19 months ago, rsa 18 days ago.
Also in this space
Method
Real downloads = the median day with no release that day or the day before, from the crates.io API (Jul 27, 2026 to Oct 23, 2026). Raw crates.io counts include CI and bots and run high (why); the method is from our 90-day study.
Up next
Another comparison: Same method, same window. Foundational and steady vs widely used and steady.reqwest vs ureqRead it next →Also worth your time