Companies Using Python

I run the crawler that stores the response headers of every domain we visit, and Python is the language row I trust least at face value. A domain counts when its Server header contains "Python". Our October 2026 crawl puts that at 6,438 domains after cleaning, 4th of 13 in Programming Languages, with 3,665 matched to a company. On 16 October 2026 I re-requested a random 7% of the domains, 592 of them, 422 of which survive the cleaning, along with every one of the 1,873 domains with no stored page title, and resolved the sample to its networks. Our guide to technology detection methods explains how header rules work.

A quarter of the raw count was for sale

The biggest cluster in the raw sample was a domain marketplace. 161 of the 592 (27.2%) resolved to one American network, 123.Net, and every one served a page titled "For Sale | Appraise.net Marketplace" with the banner Apache/2.4.58 (Ubuntu) OpenSSL/3.0.13 mod_wsgi/5.0.0 Python/3.12. Across the whole set I counted 2,384 for-sale pages: 1,537 Appraise.net pages caught by their stored titles, 845 more among the untitled domains once I loaded them, and 2 other parked pages. They are a domain marketplace's inventory, not Python customers, so they're out of every figure on this page.

"More than a quarter of the domains that said Python were one marketplace's for-sale pages. The marketplace runs Python; the domains don't." - David Thomson, CTO at TechnologyChecker.io

Sales signal: if you build a Python list from raw header data elsewhere, drop any row titled "For Sale" or answering with that exact banner first.

What the rest is

Of the 372 cleaned sample domains that sent a Python banner, 129 ran Werkzeug, and 105 of those carried Odoo's web assets: self-hosted Odoo servers facing the internet directly, some still titled "Home | My Website". 124 ran Apache with mod_wsgi, 48 were PythonAnywhere apps, 30 were Zope servers and 28 used the old mod_python module. On the full clean set Odoo shows on 1,751 domains (27.2%), and PythonAnywhere hosts 11.93%.

Sales signal: the Odoo group is a real segment. They are businesses running their own ERP, and they need hosting, security and Odoo services.

Old versions in plain sight

Python servers print their version, so this row shows its age openly. Of those 372 banners, 92 announced Python 2, 83 of them 2.7, usually the mod_wsgi/3.4 Python/2.7.5 pairing on Apache 2.4.6 builds labelled CentOS or Red Hat Enterprise Linux. Python.org's Python 2 sunset page says the project stopped improving Python 2 on 1 January 2020, even for security problems. All 30 Zope banners in the sample ran Python 2, 22 of them Zope 2.13 on Python 2.7 and one as old as Python 2.1.

Sales signal: a Python 2 banner is a dated, public upgrade problem with an owner. Migration and managed-hosting offers have a clear opening.

How much of it is current

372 of the 422 cleaned domains (88.15%) still sent a Python banner on 16 October 2026. 22 didn't answer, 9 returned an error and 12 showed placeholders, mostly PythonAnywhere's "Coming Soon" page for a domain with no app behind it; 74 domains in the clean set show that page. Since we began tracking on 16 March 2026, 1,099 domains dropped the banner on at least one hostname, and 99 of those still send it from another. We chart only October 2026, because earlier months predate the cleaning, and any month-to-month view mixes in our side: the set of domains we crawl turns over every month, dead sites out and newly found ones in, and our detection widens.

Sales signal: close to nine in ten rows are live servers worth contacting.

Who and where

The United States has only 540 of the 3,665 matched companies (14.73%); Germany has 337, France 276, Spain 217 and Brazil 190. 60.21% of companies with a known size employ 1 to 10 people, IT services and software firms make up 15.82%, and 72.16% of companies with a founding year date from 2000 or later. The large names are institutions: the Space Telescope Science Institute's Hubble Legacy Archive, the College of American Pathologists, and Brazil's CGU and Serpro on Plone.

Sales signal: this list leans European. Localise outreach, and lead with ERP and hosting services rather than developer tools.

Overlap with other languages

We publish no switching rows for Python. 1,910 domains run Python and PHP today, and 63 of the 372 cleaned sample banners list PHP and Python in the same line. 317 run Python and Perl, often one banner listing mod_wsgi and mod_perl side by side. Of the 3,611 domains that ran Python and PHP together at some point since March, 1,910 (52.9%) still do.

"A banner with PHP, mod_wsgi and mod_perl in one line is a server somebody configured years ago and still pays to keep running." - David Thomson, CTO at TechnologyChecker.io

Sales signal: multi-language Apache servers are consolidation candidates. Pitch the owner on simplifying, not on switching languages.

The stack around it

Across the 6,438 clean domains, Apache HTTP Server answers on 46.19% and mod_wsgi on 34.9%. Flask shows on 32.29%, Zope on 8.11%, Plone on 5.58% and Django on 5.3%. PythonAnywhere hosts 11.93%, and its own pricing page lists a free Beginner account and a $10-a-month Developer plan with a custom domain. On the network side the cleaned sample spreads across Amazon (12.32%), Hetzner (7.82%) and OVH (6.64%).

Sales signal: PythonAnywhere's custom-domain users are on paid plans, though 74 of them have no app live yet.

Key takeaways

1. 6,438 domains name Python in the Server header after cleaning; 88.15% of a random 422 still did on 16 October 2026.

2. We removed 2,384 for-sale pages first, 2,382 of them Appraise.net's.

3. Odoo is the largest real group, with 1,751 domains.

4. 92 of 372 sampled banners still announce Python 2.

How to use this list

Split it by banner: Werkzeug and Odoo for ERP and hosting offers, mod_wsgi and Python 2 for migration work, Zope and Plone for public-sector web services. The full list of 6,438 domains, with 3,665 matched companies, is on TechnologyChecker.io.