Crates / Compare / heck vs convert_case
Rust crates side by side · data Oct 24, 2026
heck vs convert_case
Short answerBy steady daily use, heck is bigger: 3,901,922 real downloads a day against 1,687,092 for convert_case (2.3x). 1,865 crates depend on heck and 1,213 on convert_case. heck last shipped 2.6 years ago, convert_case 58 days ago.
heck
Widely usedWidely used and quiet for years.
1,865 crates depend on it; no release in the last 90 days, so its count is all steady use.
heck is a case conversion library.
convert_case
Widely usedWidely used and steady.
1,213 crates depend on it; downloads don't spike on releases.
Convert strings into any case
heckconvert_case · 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 | heck | convert_case |
|---|---|---|
| Real downloads a day | 3,901,922 | 1,687,092 |
| Crates that depend on it | 1,865 | 1,213 |
| Last release | 0.5.0, 2.6 years ago | 0.12.0, 58 days ago |
| Trend vs the field | -4% | -2% |
| Release-window share | 0.0% | 2.4% |
| Downloads in the window | 336,400,089 | 148,898,535 |
| All-time downloads | 1,452,205,164 | 598,281,440 |
| Versions published | 11 | 15 |
| License | MIT OR Apache-2.0 | MIT |
| MSRV | 1.56 | not set |
| First published | Mar 27, 2017 | Apr 17, 2020 |
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 (heck, 1,865 dependents): more eyes, more answered questions, and you may already have it in your tree.
- Check the release dates against your own pace: heck 2.6 years ago, convert_case 58 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.
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