Crates / wasmparser
Rust crate · real downloads · data Oct 24, 2026
wasmparser downloads, and should you depend on it?
A simple event-driven library for parsing WebAssembly binary files. crates.io · docs.rs · repository
Owned on crates.io by wasmtime-publish · alternatives · is it still maintained?
Feature flags + Cargo.toml picker
Established and steady.
wasmparser: 431 crates depend on it; downloads don't spike on releases.
How this verdict is decided (4 rules)
- Usage: crates.io reverse dependencies (crates that list it as a dependency): 10,000+ = foundational, 1,000+ = widely used, 100+ = established, under 100 = few direct dependents.
- Direction: the median quiet day in the last 30 days of the window against the first 30, read against the median tracked crate (the whole field moved +39% from late summer to October, so a raw trend says nothing). 10%+ ahead of the field = gaining; 10%+ behind = losing ground; otherwise steady. Steady with no release in 2+ years = quiet for years.
- Release spikes: the median release-window day against the quiet-day baseline: under 1.15x = no spike, 1.15x to 1.3x = small bumps, 1.3x or more = jumps on release days.
- Release recency: days since the newest version that was not yanked, from crates.io publish times.
release window (release day + next day)quiet dayquiet-day median · download the 89 days as CSV
The numbers in one paragraphwasmparser got 90,715,578 crates.io downloads from Jul 27, 2026 to Oct 23, 2026. 20% of them landed within 2 days of one of its 11 releases. On the other 73 quiet days it got a median of 1,023,280 a day, about 7,162,960 a week. Capping release days at that baseline leaves 88,664,707 release-adjusted downloads for the window.
What this means if you're choosing a dependency
- Used, not everywhere. 431 crates depend on it. Look at how fast its issues get answered before you lean on it.
- Actively released. 0.262.0 shipped 11 days ago (Oct 13, 2026).
- Still pre-1.0 (0.262.0). Under Cargo's semver rules a 0.x minor bump may break you, so pin the minor version (
wasmparser = "0.262") and read the changelog on upgrades. - Fit check: license Apache-2.0 WITH LLVM-exception OR Apache-2.0 OR MIT, edition 2024, needs Rust 1.88.0 or newer (from the latest version's manifest).
- Compare it by the baseline, not the raw count. 20% of its 90,715,578 downloads in the window landed within 2 days of a release; the steady number is 1,023,280 a day.
Alternatives that do a similar job
Crates that share its crates.io category or keywords, most similar first. Each line is the crate's own description, then how it compares on the same data.
Its place in the dependency graph
Built on wasmparser
5 of the 1000 crates we track depend on it directly (biggest first).
wasmparser builds on
Tracked crates its latest version (0.262.0) depends on (optional ones marked).
What the chart says
- Weekend quiet days ran at 62% of weekday quiet days (678,312 vs 1,099,993). A dip that deep is the signature of work-week CI pipelines and developers building on weekdays.
- Biggest day: 1,489,472 on Oct 21, 2026, a quiet day with no release nearby.
Every number
| All-time downloads | 274,023,987 (rank #463 on crates.io by all-time downloads) |
| Downloads in the window | 90,715,578 (Jul 27, 2026 to Oct 23, 2026, 89 days) |
| Within 2 days of a release | 18,093,734 (19.9%) |
| Quiet-day median (baseline) | 1,023,280 a day; weekdays 1,099,993, weekends 678,312 |
| Release-adjusted downloads | 88,664,707 (release-window days capped at the baseline) |
| Baseline rank | #378 of the 1000 crates we track |
| Quiet-day trend | +30% raw, -6% against the median tracked crate (+39%) |
| Releases in the window | 11 |
| Versions published, ever | 292 |
| Latest version | 0.262.0, published Oct 13, 2026 (license Apache-2.0 WITH LLVM-exception OR Apache-2.0 OR MIT, edition 2024, MSRV 1.88.0) |
| First published | Jun 2, 2017 |
| Reverse dependencies | 431 |
Releases in the window
Each one opens a 2-day release window on the chart.
| Version | Published | Downloads that version got (lifetime) |
|---|---|---|
| 0.262.0 | Oct 13, 2026 | 321,779 |
| 0.258.3 | Oct 2, 2026 | 480,263 |
| 0.254.2 | Oct 2, 2026 | 552,009 |
| 0.261.0 | Oct 2, 2026 | 746,297 |
| 0.260.0 | Sep 30, 2026 | 144,017 |
| 0.259.0 | Sep 10, 2026 | 1,630,751 |
| 0.258.0 | Aug 24, 2026 | 1,497,832 |
| 0.257.1 | Aug 19, 2026 | 544,898 |
| 0.257.0 | Aug 19, 2026 | 2,706 |
| 0.256.0 | Aug 10, 2026 | 467,940 |
| 0.255.0 | Jul 30, 2026 | 650,177 |
How we compute this
crates.io counts every download, including CI runners, mirrors and bots that fetch each new version, so raw counts run high (why, in The Manual). We split the last 89 days into release windows (the day a version of wasmparser was published, plus the next day) and quiet days, and use the median quiet day as the baseline: an upper bound on steady use, never a head count. The method and data come from our study of 90 days of crates.io data from 69 crates, featured in This Week in Rust #674; check any crate live with the real-downloads checker.
Badge for your README
Maintainers can show the baseline in a README. It is optional, updates when we refresh the data, and links back here. Preview, then copy:
README, light
README, dark
Publishing a crate of your own? How to publish a Rust crate to crates.io, step by step.
Categories
Sources
- Daily downloads: crates.io API, /crates/wasmparser/downloads (last 90 days, all versions), fetched Oct 24, 2026.
- Versions and publish times: crates.io API, /crates/wasmparser/versions, same fetch.
- Reverse dependencies: crates.io reverse dependencies, same fetch. Dependency edges between tracked crates: each crate's default version, crates.io API.
- Fetched politely (one request every 2 seconds, identified User-Agent) per the crates.io data access policy. Data is crates.io's; the release-window split, baseline and verdict rules are ours, CC BY 4.0.
Up next
Next by real downloads: The next crate down the real-downloads ranking: 1,018,499 a day. Widely used and steady.bindgenRust crate. Automatically generates Rust FFI bindings to C and C++ libraries. Real use: 1M downloads a day on quiet days; 3,072 crates depend on it.Read it next →Also worth your time