PyRank
horejsek

fastjsonschema

Fast JSON schema validator for Python.
PyPI GitHub
No known security advisories. The current version has no OSV.dev malware reports and no critical or high-severity vulnerabilities.

fastjsonschema has 150.8M monthly downloads and 491 GitHub stars. Version 2.21.2, first published in 2016.

It is stably maintained under a permissive license, last released in Aug 2025.

It is used by 229 tracked packages, including poetry, nbformat and datacontract-cli.

Downloads
Day
4.3M
Week
32.5M
Month
150.8M
Stars
491
Forks
75
Issues
7
Version
2.21.2

Package Insights

What's this?
Score breakdown - each component scores 0-100, weighted by percentage
Maintenance
80
Popularity
56
Adoption
70
Community
50
Provenance
0
How the maintenance status was determined
Last commit
44 days ago
Monthly downloads
150,781,908
Active
Activity within 30 days
• Stable
Activity within 31-180 days
Minimal
Activity within 181-365 days, or no activity data
At Risk
No activity for > 365 days, but > 10,000 monthly downloads
Archived
Repository flagged as archived on GitHub
How the popularity category was determined
Monthly downloads
150,781,908
Stars
491
Stars per 1k downloads
0.00
• Industry Standard
> 10,000,000 monthly downloads
Hidden Gem
< 0.5 stars per 1k downloads and > 100,000 monthly downloads
Community Favorite
> 5 stars per 1k downloads
Rising Star
Balanced ratio of stars to downloads
Unknown
Fewer than 1,000 monthly downloads, or no star data
How download momentum is calculated
Week daily avg
4,640,029
Month daily avg
5,026,064
Momentum
-7.7%
((week_daily_avg - month_daily_avg) / month_daily_avg) * 100
Python version support tiers
requires_python
Not specified
Cutting Edge
Minimum supported version is 3.12 or newer
Modern
Minimum supported version is 3.9, 3.10, or 3.11
Legacy
Supports 3.8 or older (or Python 2)
• Unknown
No requires_python specified or unparseable
Package does not declare a minimum Python version.
License categories
License
BSD
• Permissive
MIT, Apache, BSD, ISC, Unlicense, CC0, etc.
Copyleft
GPL, LGPL, AGPL, MPL, EPL, etc.
Proprietary
Commercial, all rights reserved, custom EULAs
Unknown
No license specified, or none of the above match
How the release cadence was determined
Last release
326 days ago
Total releases
45
Releases/year
4.6
Rapid
Last release within 365 days and > 12 releases/year
• Regular
Last release within 365 days
Slow
Last release 366-730 days ago
Stalled
Last release > 730 days ago, or no releases
Unknown
No usable release date available
How contributor risk was determined
Contributors
30
Monthly downloads
150,781,908
High Load
≤ 2 contributors and ≥ 50,000 monthly downloads
Moderate Load
< 10 contributors and ≥ 500,000 monthly downloads
Low Load
< 25 contributors and ≥ 5,000,000 monthly downloads, or sole maintainer with ≥ 10,000 monthly downloads
• Balanced
Enough contributors for the package's popularity
Unknown
No contributor data available
Engagement
47
 
Issue Burden
14.3
per 1k stars
Discussions
0.0
per 1k stars
Fork Ratio
40.0%
contrib / forks
Stale Release
281d
 
PR Velocity
Quiet
 

Weekly Downloads

GitHub Stars

Not all downloads include detailed metadata. Breakdowns reflect the subset that does.

Downloads by OS

Linux 2.5M
Windows 53.4K
macOS 36.8K

Python Versions

3.12
30.8% 694.3K
3.11
24.1% 544.2K
3.10
20.4% 460.9K
3.9
15.2% 343.1K
3.13
9.4% 212.5K

Top Countries

1. US US
2.0M
2. IE IE
99.4K
3. NL NL
80.7K
4. SG SG
65.0K
5. DE DE
62.7K
6. JP JP
23.8K
7. GB GB
23.6K
8. IN IN
23.0K
9. AU AU
22.1K
10. FR FR
15.6K

Package Information

License
BSD
First Release
October 5, 2016
Last Release
10 months ago
Last Commit
1 month ago
Latest Version
2.21.2
Total Releases
45
Contributors
30
Open PRs
1
Archived
No
Author
Michal Horejsek
Python Versions
3 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13
Wheels
py3
Tracking Since
January 6, 2026
Data Updated
July 5, 2026
Data Freshness
Fresh

Links