Fastify VS Windows Communication Foundation
As of 30 October 2026, Windows Communication Foundation is named by 387 companies and Fastify by 139; Fastify skews to companies under 200 people (58% vs 51%), Windows Communication Foundation to companies over 1,000 (23% vs 22%).
As of 30 October 2026 · refreshed daily · counts move as websites, DNS and career sites are re-read.
The website-and-DNS footprint is not comparable between a marketing suite and a CRM: Fastify's script and mail records show on hundreds of thousands of small sites, Windows Communication Foundation rarely leaves a trace outside its own apps. Compare on the job-posting numbers; use the footprint for reach.
- Fastify: 2–200 employees
- 58%
- Windows Communication Foundation: 2–200 employees
- 51%
- Fastify: 1,000+ employees
- 22%
- Windows Communication Foundation: 1,000+ employees
- 23%
- Postings per company, 90 days
- 2.9 · 2.0
- Website or DNS footprint
- 0 · 0
Who chooses which
Share of each tool's companies in every segment. "Leans" marks a gap of more than two points.
| Segment | Fastify | share | Windows Communication Foundation | share | Leans |
|---|---|---|---|---|---|
| Self-employed | 3 | 2% | 3 | 1% | even |
| 2-10 employees | 15 | 11% | 27 | 7% | Fastify |
| 11-50 employees | 33 | 24% | 87 | 22% | even |
| 51-200 employees | 32 | 23% | 83 | 21% | even |
| 201-500 employees | 14 | 10% | 59 | 15% | Windows Communication Foundation |
| 501-1000 employees | 12 | 9% | 39 | 10% | even |
| 1001-5000 employees | 13 | 9% | 45 | 12% | Windows Communication Foundation |
| 5001-10000 employees | 2 | 1% | 12 | 3% | even |
| 10,001+ employees | 15 | 11% | 32 | 8% | Fastify |
| Segment | Fastify | share | Windows Communication Foundation | share | Leans |
|---|---|---|---|---|---|
| Technology & software | 88 | 63% | 248 | 64% | even |
| Business & finance services | 23 | 17% | 66 | 17% | even |
| Manufacturing & industry | 6 | 4% | 28 | 7% | Windows Communication Foundation |
| Consumer services & leisure | 4 | 3% | 7 | 2% | even |
| Media & content | 3 | 2% | 6 | 2% | even |
| Automotive | 2 | 1% | 2 | 1% | even |
| Commerce & trade | 2 | 1% | 2 | 1% | even |
| Public, community & associations | 2 | 1% | 3 | 1% | even |
| Health care | 2 | 1% | 3 | 1% | even |
| Hospitality & travel | 2 | 1% | 3 | 1% | even |
| Property & construction | 2 | 1% | – | – | outside top 12 |
| Agriculture & forestry | 1 | 1% | – | – | outside top 12 |
| Transport, logistics & rental | – | – | 9 | 2% | outside top 12 |
| Utilities & infrastructure | – | – | 7 | 2% | outside top 12 |
| Segment | Fastify | share | Windows Communication Foundation | share | Leans |
|---|---|---|---|---|---|
| United States | 80 | 58% | 205 | 53% | Fastify |
| Germany | 7 | 5% | 12 | 3% | even |
| France | 6 | 4% | 11 | 3% | even |
| United Kingdom | 6 | 4% | 24 | 6% | even |
| India | 6 | 4% | 42 | 11% | Windows Communication Foundation |
| Brazil | 5 | 4% | – | – | outside top 12 |
| Poland | 4 | 3% | 7 | 2% | even |
| Belgium | 3 | 2% | 7 | 2% | even |
| Italy | 3 | 2% | 7 | 2% | even |
| Netherlands | 3 | 2% | – | – | outside top 12 |
| Canada | 2 | 1% | 8 | 2% | even |
| Singapore | 2 | 1% | – | – | outside top 12 |
| Australia | – | – | 8 | 2% | outside top 12 |
| Spain | – | – | 5 | 1% | outside top 12 |
| United Arab Emirates | – | – | 3 | 1% | outside top 12 |
| Segment | Fastify | share | Windows Communication Foundation | share | Leans |
|---|---|---|---|---|---|
| Software engineering | 440 | 90% | 1,707 | 83% | Fastify |
| Data & AI | 10 | 2% | 8 | 0% | even |
| Engineering (non-software) | 5 | 1% | 9 | 0% | even |
| IT operations & business systems | 5 | 1% | 92 | 4% | Windows Communication Foundation |
| Marketing & communications | 1 | 0% | 6 | 0% | even |
| Sales | 1 | 0% | – | – | outside top 12 |
| Finance & accounting | – | – | 16 | 1% | outside top 12 |
| Product, program & project management | – | – | 12 | 1% | outside top 12 |
| Customer service & success | – | – | 4 | 0% | outside top 12 |
| Unclassified | – | – | 4 | 0% | outside top 12 |
| Administration & office | – | – | 1 | 0% | outside top 12 |
| Human resources | – | – | 1 | 0% | outside top 12 |
| Logistics warehouse and transport | – | – | 1 | 0% | outside top 12 |
The companies behind each column
Companies using Fastify →
Companies using Windows Communication Foundation →
backend frameworks ranked →
Quote the sentence with the date and the link. The numbers change daily; the link always shows the current ones.
Windows Communication Foundation is named by 387 companies in job postings and Fastify by 139; 0 name both. (Breaknorm, 30 October 2026, https://breaknorm.co/compare/fastify-vs-wcf)
Read from the source, not self-reported
Every number on this page can be traced to a page we crawled or a posting we read. Full methodology →
- Job postingsRead hourly from career sites. A tool counts when the employer's own text names it as the team's system; both tools can count for one company.
- Website and DNSScripts and embeds on the company's pages, plus SPF, DKIM, MX and CNAME records of its domain that point at the vendor.
- SegmentsCountry, size and industry from the company profile built from its website.
- Not a reviewNo ratings, prices or feature claims. For those, read the vendors.
Fastify vs Windows Communication Foundation: questions
Which is more used, Fastify or Windows Communication Foundation?
By companies naming it in their own job postings, Windows Communication Foundation (387) over Fastify (139). By website-and-DNS footprint, Windows Communication Foundation (0 vs 0), because its scripts and mail records sit on many small company sites.
Who chooses Fastify?
58% of Fastify companies have 2 to 200 employees, against 51% for Windows Communication Foundation. 22% of Fastify companies have over 1,000 employees, against 23% for Windows Communication Foundation.
Do companies run both?
0 companies name both in their postings, usually Fastify in marketing and Windows Communication Foundation in sales, or during a migration.
Where do these numbers come from?
From the employer's own text in job postings read hourly from career sites, and from scripts found on company websites in our crawl. No vendor data, no surveys.
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