# Werkzeug, what it is and how websites use it.

A Python library for web applications (WSGI) that Flask is built on. It also includes a development server.

- **Status:** Stable. A Werkzeug server header in production usually means Flask's development server, which is not meant for production.
- **Category:** [Servers & Hosting](https://be1st.ai/technologies/server)
- **First release:** 2007
- **License:** BSD-3-Clause
- **Official website:** https://werkzeug.palletsprojects.com
- **Documentation:** https://werkzeug.palletsprojects.com/en/stable/
- **GitHub:** https://github.com/pallets/werkzeug
- **Page:** https://be1st.ai/technologies/server/werkzeug

## Werkzeug on audited websites

1 of the 16,845 websites audited by be1st run Werkzeug (<1%). That ranks it #34 of the 34 technologies in Servers & Hosting we have seen in audits.

### Most used in Servers & Hosting

1. [Cloudflare](https://be1st.ai/technologies/server/cloudflare): 22% (3,772)
2. [Vercel](https://be1st.ai/technologies/server/vercel): 22% (3,635)
3. [Google CDN](https://be1st.ai/technologies/server/google-cdn): 16% (2,700)
4. [nginx](https://be1st.ai/technologies/server/nginx): 14% (2,284)
5. [OpenResty](https://be1st.ai/technologies/server/openresty): 10% (1,707)
6. [Apache HTTP Server](https://be1st.ai/technologies/server/apache-http-server): 9.3% (1,574)
7. [jsDelivr](https://be1st.ai/technologies/server/jsdelivr): 7.2% (1,221)
8. [cdnjs](https://be1st.ai/technologies/server/cdnjs): 6.0% (1,019)
9. [Netlify](https://be1st.ai/technologies/server/netlify): 5.8% (971)
10. [AWS CloudFront](https://be1st.ai/technologies/server/aws-cloudfront): 5.1% (859)

We don't track the release history of Werkzeug yet. Its releases are published on GitHub. https://github.com/pallets/werkzeug/releases

## Other technologies in Servers & Hosting

- [unpkg](https://be1st.ai/technologies/server/unpkg): 2.8% of websites
- [Fastly](https://be1st.ai/technologies/server/fastly): 1.6% of websites
- [BunnyCDN](https://be1st.ai/technologies/server/bunnycdn): 1.2% of websites
- [Microsoft IIS](https://be1st.ai/technologies/server/microsoft-iis): 1.0% of websites
- [LiteSpeed](https://be1st.ai/technologies/server/litespeed): <1% of websites
- [Caddy](https://be1st.ai/technologies/server/caddy): <1% of websites
- [Amazon S3](https://be1st.ai/technologies/server/amazon-s3): <1% of websites
- [Google Cloud](https://be1st.ai/technologies/server/google-cloud): <1% of websites
- [Varnish](https://be1st.ai/technologies/server/varnish): <1% of websites
- [Azure](https://be1st.ai/technologies/server/azure): <1% of websites
- [Hostinger CDN](https://be1st.ai/technologies/server/hostinger-cdn): <1% of websites
- [GitHub Pages](https://be1st.ai/technologies/server/github-pages): <1% of websites

[All 35 in Servers & Hosting](https://be1st.ai/technologies/server)

## Questions about Werkzeug

### What is Werkzeug?

A Python library for web applications (WSGI) that Flask is built on. It also includes a development server. The be1st catalog lists Werkzeug under Servers & Hosting. License of Werkzeug: BSD-3-Clause.

### How many websites use Werkzeug?

1 of the 16,845 websites audited by be1st run Werkzeug (<1%), as of 8 Nov 2026.

### When was Werkzeug first released?

Werkzeug was first released in 2007.

### Is Werkzeug still a modern choice?

Werkzeug is a stable, mature choice rather than a new one. A Werkzeug server header in production usually means Flask's development server, which is not meant for production.

Numbers: latest audit of each of 16,845 websites audited by be1st, as of 8 Nov 2026.