# Outsend, free: Tech stack API

> Detect the technologies powering each prospect's website (CMS, JavaScript frameworks, analytics suites, payment processors, hosting and CDN) and return one structured row per site.

Outsend's tech stack API on its Alpha plan. It costs $0.00 per 1,000 companies. Outsend's docs list 2 of the 13 key fields we check: Technology, About.
You get up to 9,000 calls a month.
We haven't run Outsend through [our tech stack API benchmark](https://datacircle.dev/best-tech-stack-api.txt) yet.
This plan is free. We rank 354 plans for tech stack APIs by price. Half the plans cost $7.96 per 1,000 companies or less.
[cl0q's $50 monthly plan](https://datacircle.dev/company-technology-apis/cl0q/50-monthly/llms.txt) is the cheapest paid plan per 1,000 companies: $0.0042.
[GetProspect's $49 monthly plan](https://datacircle.dev/company-technology-apis/getprospect/49-monthly/llms.txt) covers any number of companies. GetProspect's $49 monthly plan costs less up front than cl0q's $50 monthly plan.
[JobsPipe](https://datacircle.dev/company-technology-apis/jobspipe/149-monthly-growth-post-v1-stack-scan/llms.txt), [DetectZeStack](https://datacircle.dev/company-technology-apis/detectzestack/79-monthly-mega-get-analyze/llms.txt) and [GetProspect](https://datacircle.dev/company-technology-apis/getprospect/49-monthly/llms.txt) are the best tech stack API providers in the Datacircle benchmark.

- This page: https://datacircle.dev/company-technology-apis/outsend/free
- [Tech stack API: find a company's technologies](https://datacircle.dev/best-tech-stack-api.txt)
- Get it: https://outsend.xyz/en/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=tech-stack-api-pricing
- Request: `POST https://outsend.xyz/api/jobs/techstack`
- API key: with the plan, on https://outsend.xyz/en/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=tech-stack-api-pricing
- Its API docs: https://outsend.xyz/docs/modules/techstack?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=tech-stack-api-pricing
- Sold by: Outsend (https://outsend.xyz?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=tech-stack-api-pricing)
- Checked: 2026-11-06

## In the answer

- Completeness: 15%
- Technology: ✓
- About: ✓

## Price

- $ per 1,000 companies: $0.00
- Per: result
- Billing: free

## Aggregators

- Aggregators: none

## Charges

- Also pays for: from the same budget: Scrap (Google Maps) · SIRENE registry · Reviews · Emails · Socials · Extra phones · Public-registry enrichment · Find the website · Business IDs · Legal mentions · French legal data · Financial data · Pricing · PageSpeed · Ads profile · Brand assets · Closed check · Phone info · Email verification · Inbox placement

## Not found

- $ per 1,000: $0.00

## In their words

- Their pitch: Detect the technologies powering each prospect's website (CMS, JavaScript frameworks, analytics suites, payment processors, hosting and CDN) and return one structured row per site.

## Data

- Freshness: live
- Keep data: no limit
- Use data: The data collected by the user through outsend (scraping results, enrichments, filtered lists, notes, monitoring) remains the property of the user. [...] The following are strictly prohibited, on pain of immediate account suspension without notice or refund: Spam, harassment, mass sending of unsolicited messages in breach of GDPR, e-Privacy or CAN-SPAM, Outreach to private individuals without a legal basis (prior consent required for B2C in France), Collection or use of sensitive data within the meaning of GDPR (health, political/religious views, sexual orientation, biometric data, etc.), Resale, public sharing or transfer to a third party of leads collected through outsend, unless explicit agreement with that third party and GDPR compliance, Use of outsend for illegal, fraudulent activities or activities harming third parties, Any attempt to bypass outsend's security measures or access other users' data. [...] The user commits to respecting, when using the collected data: GDPR: legal basis of processing, information of data subjects, data subject rights (access, deletion, objection), The French Data Protection Act (Loi Informatique et Libertés), Article L.34-5 of the French Postal and Electronic Communications Code on electronic outreach, CNIL recommendations on B2B outreach (in particular clear opt-out, sender identification, respect of objections).

## Plan

- Pay: $0
- Enough for: 9,000 calls a month

## Rate limit

- Per day: 300
- Concurrent: 5
- Batch: 10,000

## Speed

- Answer: by polling or webhook

## The call

- You send: items[].site_web. Optional: source_job_id
- Method: POST
- Path: /api/jobs/techstack

## About the plan

- Plan: Alpha
- Who can get it: anyone with an account, within the seats opened each day during the alpha

## The 24 fields the plan's answer can hold

URL status, CMS, CMS version, CMS outdated, page builder, JavaScript frameworks, CSS frameworks, analytics, marketing and CRM tools, chat widgets, payment providers, e-commerce platforms, hosting and CDN, tag managers, A/B testing tools, compliance tools, advertising pixels, WordPress plugins, schema.org types, schema.org phone, schema.org address, schema.org opening hours, technology alerts, technologies

## Outsend's plans (2)

- [Outsend, free](https://datacircle.dev/company-technology-apis/outsend/free/llms.txt): $0.00 per 1,000, 15% complete, live
- [Outsend, top-up](https://datacircle.dev/company-technology-apis/outsend/top-up/llms.txt): $1.013 per 1,000, 15% complete, live

## Outsend's calls for this API (1)

- `POST /api/jobs/techstack`: [Outsend, free](https://datacircle.dev/company-technology-apis/outsend/free/llms.txt)

## Outsend's APIs (6)

- [Outsend: Local business reviews API pricing, 2 plans](https://datacircle.dev/local-business-reviews-apis/outsend/free/llms.txt)
- [Outsend: Local business search API pricing, 2 plans](https://datacircle.dev/local-business-search-apis/outsend/free/llms.txt)
- [Outsend: tech stack API pricing, 2 plans](https://datacircle.dev/company-technology-apis/outsend/free/llms.txt)
- [Outsend: email verification API pricing, 2 plans](https://datacircle.dev/validate-email-apis/outsend/free/llms.txt)
- [Outsend: phone validation API pricing, 1 plan](https://datacircle.dev/validate-phone-apis/outsend/free/llms.txt)
- [Outsend: business verification API pricing, 1 plan, GET /api/company/lookup](https://datacircle.dev/business-verification-apis/outsend/free-alpha-get-api-company-lookup/llms.txt)
- [Outsend: business verification API pricing, 1 plan, POST /api/jobs/legal-data](https://datacircle.dev/business-verification-apis/outsend/free-alpha-post-api-jobs-legal-data/llms.txt)

## Outsend: tech stack API alternatives

- [StackPeek, $29 monthly, Pro, GET /api/v1/detect](https://datacircle.dev/company-technology-apis/stackpeek/29-monthly-pro-get-api-v1-detect/llms.txt): $1.16 per 1,000, 23% complete, live
- [Bright Data, $499 monthly](https://datacircle.dev/company-technology-apis/bright-data/499-monthly/llms.txt): $1.30 per 1,000, 38% complete, live
- [1Lookup, $19,990 yearly, Enterprise (annual), POST /bulk/jobs](https://datacircle.dev/company-technology-apis/1lookup/19990-yearly-enterprise-annual-post-bulk-jobs/llms.txt): $1.666 per 1,000, 23% complete, live
- [AI Website Detector, €149 monthly](https://datacircle.dev/company-technology-apis/ai-website-detector/149-monthly/llms.txt): $1.677 per 1,000, 8% complete, live

## Sources

From each provider's own pricing page and docs, and from what providers tell us. We read this row from these pages on 2026-11-06.

- https://outsend.xyz/api/openapi.json?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=tech-stack-api-pricing
- https://outsend.xyz/docs/api/auth?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=tech-stack-api-pricing
- https://outsend.xyz/docs/api/overview?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=tech-stack-api-pricing
- https://outsend.xyz/docs/concepts/limits?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=tech-stack-api-pricing
- https://outsend.xyz/docs/llms-full.txt?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=tech-stack-api-pricing
- https://outsend.xyz/docs/modules/techstack?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=tech-stack-api-pricing
- https://outsend.xyz/docs/what-is-outsend?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=tech-stack-api-pricing
- https://outsend.xyz/en/cgv?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=tech-stack-api-pricing
- https://outsend.xyz/en/conditions?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=tech-stack-api-pricing
- https://outsend.xyz/en/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=tech-stack-api-pricing