subtle vs ark-serialize

Short answerBy steady daily use, subtle is bigger: 2,159,165 real downloads a day against 343,752 for ark-serialize (6.3x). 2,362 crates depend on subtle and 402 on ark-serialize. subtle last shipped 2.3 years ago, ark-serialize 6 months ago.

subtle

Widely used

Widely used and quiet for years.

2,362 crates depend on it; no release in the last 90 days, so its count is all steady use.

Pure-Rust traits and utilities for constant-time cryptographic implementations.

ark-serialize

Established

Established and steady.

402 crates depend on it; no release in the last 90 days, so its count is all steady use.

A library for serializing types in the arkworks ecosystem

subtleark-serialize · 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	subtle	ark-serialize
Real downloads a day	2,159,165	343,752
Crates that depend on it	2,362	402
Last release	2.6.1, 2.3 years ago	0.6.0, 6 months ago
Trend vs the field	-1%	+3%
Release-window share	0.0%	0.0%
Downloads in the window	200,229,434	30,066,583
All-time downloads	799,309,141	110,562,806
Versions published	29	15
License	BSD-3-Clause	MIT OR Apache-2.0
MSRV	not set	1.75
First published	May 31, 2017	Mar 24, 2021

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 (subtle, 2,362 dependents): more eyes, more answered questions, and you may already have it in your tree.
Check the release dates against your own pace: subtle 2.3 years ago, ark-serialize 6 months ago.

Also in this space

ringWidely usedAn experiment2,112,308 a day, 1,837 dependents cmovPulled inConditional move CPU intrinsics which are guaranteed on major platforms (ARM32/ARM64, x86/x86_64, RISC-V) to...852,311 a day, 3 dependents aws-lc-rsEstablishedaws-lc-rs is a cryptographic library using AWS-LC for its cryptographic operations. This library strives to...1,156,444 a day, 474 dependents digestWidely usedTraits for cryptographic hash functions and message authentication codes3,862,411 a day, 1,197 dependents

Compare 4 of them side by side →

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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