Crates / Category
Rust crates · category · data Oct 24, 2026
External FFI bindings crates by real downloads
crates.io describes this category as: “Direct Rust FFI bindings to libraries written in other languages; often denoted by a -sys suffix. Safe and idiomatic wrappers are in the API bindings category.” Below are the 20 crates in it among the 1000 most-downloaded crates, ranked by real downloads (quiet-day baseline) instead of raw count.
Short answerBy steady daily use, libc leads External FFI bindings with 4,964,021 real downloads a day (foundational and steady). 5 of the 20 have 1,000+ dependents; 2 have shipped nothing in 2+ years. Release spikes barely matter here: the median crate got 0.0% of its downloads within 2 days of a release.
20 crates
| Compare | ||||||
|---|---|---|---|---|---|---|
| libcFoundational | 4,964,021 | 17,338 | 8d | -8% | 1.8B | |
| linux-raw-sysPulled in | 3,305,436 | 39 | 10mo | -3% | 1.2B | |
| winapiWidely used | 1,251,224 | 1,603 | 6.3y | -3% | 545M | |
| winapi-utilPulled in | 1,250,242 | 67 | 14mo | +1% | 453M | |
| openssl-sysEstablished | 1,032,002 | 321 | 4mo | -12% | 488M | |
| bindgenWidely used | 1,018,499 | 3,072 | 46d | -2% | 433M | |
| libsqlite3-sysEstablished | 986,538 | 229 | 3mo | +18% | 281M | |
| security-framework-sysPulled in | 934,775 | 50 | 8mo | -1% | 346M | |
| jni-sysPulled in | 929,124 | 37 | 7mo | +2% | 223M | |
| objc2Widely used | 607,001 | 1,193 | 19d | +10% | 142M | |
| objc2-core-foundationEstablished | 539,144 | 422 | 13mo | +11% | 107M | |
| block2Established | 538,869 | 530 | 13mo | +6% | 125M | |
| system-configuration-sysPulled in | 525,102 | 8 | 2.7y | -2% | 205M | |
| objc2-foundationWidely used | 520,494 | 1,007 | 13mo | +14% | 109M | |
| inotify-sysPulled in | 496,815 | 2 | 4mo | +4% | 174M | |
| libz-sysEstablished | 455,887 | 144 | 12d | -8% | 249M | |
| bzip2-sysPulled in | 328,183 | 17 | 20mo | -13% | 168M | |
| ntapiPulled in | 293,806 | 52 | 8mo | +3% | 126M | |
| wayland-sysPulled in | 263,802 | 35 | 7mo | +34% | 88.8M | |
| cbindgenEstablished | 215,284 | 454 | 5mo | +2% | 112M |
Click a column to sort; press + to add a crate to a comparison. Real / day = median downloads on days with no release that day or the day before. Each crate's page shows its verdict and the 4 rules behind it. Why this method · this category on crates.io
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