Results for 38 of 40 languages from this run on actest1.

Unavailable in this run: Hack, Lisp. Follow the run link for failure details.

Crystal VS Kotlin benchmarks

Current benchmark data was generated on Sun Sep 27 2026, full log can be found HERE

CONTRIBUTIONS are WELCOME!

[x86_64][4 cores] Intel(R) Core(TM) i7-3687U CPU @ 2.10GHz (Model 58)

* -m in a file name stands for multi-threading or multi-processing

* -i in a file name stands for direct intrinsics usage. (Usage of simd intrinsics via libraries is not counted)

* -ffi in a file name stands for non-stdlib FFI usage

* (You may find time < time(user) + time(sys) for some non-parallelized programs, the overhead is from GC or JIT compiler, which are allowed to take advantage of multi-cores as that's more close to real-world scenarios.)

binarytrees

Input: 18

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
kotlin 1.kt 794ms 80ms 581.9MB 1017ms 130ms kotlin/jvm 21.0.12
crystal 1.cr 2516ms 29ms 57.1MB 2487ms 10ms crystal 1.11.2

Input: 15

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
kotlin 1.kt 188ms 30ms 159.7MB 233ms 30ms kotlin/jvm 21.0.12
crystal 1.cr 223ms 20ms 9.5MB 207ms 0ms crystal 1.11.2

coro-prime-sieve

Input: 4000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 2387ms 104ms 20.1MB 2310ms 60ms crystal 1.11.2
kotlin 2-m.kt 3342ms 283ms 229.6MB 12590ms 123ms kotlin/jvm 21.0.12
kotlin 1.kt 3615ms 290ms 219.6MB 4723ms 107ms kotlin/jvm 21.0.12

Input: 1000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 94ms 1.2ms 7.3MB 73ms 10ms crystal 1.11.2
kotlin 1-m.kt 738ms 7.2ms 77.4MB 1727ms 47ms kotlin/jvm 21.0.12
kotlin 2-m.kt 1625ms 206ms 97.5MB 5807ms 100ms kotlin/jvm 21.0.12

edigits

Input: 250001

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 100ms 23ms 7.2MB 83ms 3ms crystal 1.11.2

Input: 100000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 33ms 2.6ms 4.9MB 20ms 0ms crystal 1.11.2

fannkuch-redux

Input: 11

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 3642ms 13ms 2.5MB 3633ms 0ms crystal 1.11.2

Input: 10

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 295ms 1.0ms 2.5MB 280ms 0ms crystal 1.11.2

fasta

Input: 2500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 2.cr 622ms 5.2ms 2.9MB 493ms 110ms crystal 1.11.2
crystal 1.cr 864ms 8.7ms 14.1MB 743ms 100ms crystal 1.11.2

Input: 250000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 2.cr 78ms 5.8ms 2.9MB 57ms 10ms crystal 1.11.2
crystal 1.cr 94ms 2.3ms 4.0MB 70ms 7ms crystal 1.11.2

helloworld

Input: QwQ

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 2.8ms 0.5ms 2.5MB 0ms 0ms crystal 1.11.2
kotlin 1-m.kt 87ms 4.3ms 46.2MB 136ms 12ms kotlin/jvm 21.0.12

http-server

Input: 3000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 4232ms 927ms 223.2MB 540ms 507ms crystal 1.11.2
kotlin 2-m.kt 9841ms 283ms 341.7MB 32387ms 3343ms kotlin/jvm 21.0.12
kotlin 1-m.kt 11376ms 242ms 433.1MB 37790ms 4520ms kotlin/jvm 21.0.12

Input: 500

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 1222ms 100ms 62.3MB 63ms 77ms crystal 1.11.2
kotlin 2-m.kt 3791ms 276ms 249.0MB 11797ms 810ms kotlin/jvm 21.0.12
kotlin 1-m.kt 3917ms 180ms 275.4MB 12153ms 857ms kotlin/jvm 21.0.12

lru

Input: 1000 1000000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 0-unsafe.cr 55ms 2.8ms 2.9MB 40ms 0ms crystal 1.11.2
crystal 1.cr 88ms 0.3ms 2.4MB 80ms 0ms crystal 1.11.2
kotlin 1-m.kt 284ms 4.7ms 95.4MB 503ms 33ms kotlin/jvm 21.0.12
kotlin 2-m.kt 389ms 13ms 99.5MB 863ms 27ms kotlin/jvm 21.0.12

Input: 1000 3000000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 0-unsafe.cr 155ms 2.1ms 2.5MB 147ms 0ms crystal 1.11.2
crystal 1.cr 260ms 6.8ms 2.5MB 250ms 0ms crystal 1.11.2
kotlin 1-m.kt 482ms 4.8ms 201.4MB 717ms 47ms kotlin/jvm 21.0.12
kotlin 2-m.kt 543ms 5.7ms 209.8MB 993ms 67ms kotlin/jvm 21.0.12

Input: 100 500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 0-unsafe.cr 32ms 3.0ms 2.5MB 23ms 0ms crystal 1.11.2
crystal 1.cr 47ms 2.2ms 2.5MB 37ms 0ms crystal 1.11.2
kotlin 1-m.kt 255ms 1.9ms 91.1MB 500ms 37ms kotlin/jvm 21.0.12
kotlin 2-m.kt 302ms 15ms 95.4MB 693ms 23ms kotlin/jvm 21.0.12

mandelbrot

Input: 5000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 507ms 1.0ms 9.4MB 493ms 0ms crystal 1.11.2

Input: 1000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 27ms 0.6ms 6.1MB 20ms 0ms crystal 1.11.2

merkletrees

Input: 17

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
kotlin 1.kt 641ms 8.2ms 676.7MB 820ms 93ms kotlin/jvm 21.0.12
crystal 1.cr 1329ms 15ms 65.7MB 1307ms 10ms crystal 1.11.2

Input: 15

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
kotlin 1-m.kt 250ms 11ms 205.0MB 363ms 67ms kotlin/jvm 21.0.12
crystal 1.cr 270ms 3.0ms 23.9MB 253ms 0ms crystal 1.11.2

nbody

Input: 5000000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 2.cr 632ms 1.1ms 3.0MB 620ms 0ms crystal 1.11.2
crystal 1.cr 636ms 6.6ms 3.0MB 623ms 0ms crystal 1.11.2
kotlin 1.kt 884ms 6.3ms 49.9MB 980ms 17ms kotlin/jvm 21.0.12

Input: 500000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 2.cr 68ms 0.7ms 3.0MB 57ms 0ms crystal 1.11.2
crystal 1.cr 68ms 2.8ms 3.0MB 60ms 0ms crystal 1.11.2
kotlin 1-m.kt 208ms 14ms 49.7MB 297ms 17ms kotlin/jvm 21.0.12

nsieve

Input: 12

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 2.cr 597ms 9.0ms 11.8MB 580ms 0ms crystal 1.11.2
crystal 1.cr 1077ms 11ms 42.4MB 1060ms 0ms crystal 1.11.2

Input: 10

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 2.cr 116ms 1.9ms 5.3MB 100ms 0ms crystal 1.11.2
crystal 1.cr 210ms 7.1ms 21.0MB 197ms 0ms crystal 1.11.2

pidigits

Input: 8000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 3508ms 129ms 5.6MB 3480ms 10ms crystal 1.11.2
kotlin 1.kt 5427ms 177ms 419.0MB 6873ms 170ms kotlin/jvm 21.0.12

Input: 4000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 831ms 12ms 4.3MB 807ms 3ms crystal 1.11.2
kotlin 1-m.kt 1629ms 66ms 362.2MB 3007ms 117ms kotlin/jvm 21.0.12

spectral-norm

Input: 8000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 11056ms 4.8ms 3.9MB 11043ms 0ms crystal 1.11.2

Input: 4000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 2769ms 0.6ms 3.9MB 2757ms 0ms crystal 1.11.2

Input: 2000

lang code time stddev peak-mem mem time(user) time(sys) compiler compiler/runtime
crystal 1.cr 699ms 4.1ms 3.5MB 687ms 0ms crystal 1.11.2