OP3
What it is
OP3 is a free, open-source service for measuring podcast episode downloads through a prefix added to episode URLs in a podcast feed. Each show measured by OP3 receives a public stats page with download metrics, detailed breakdowns, and spreadsheet exports covering its history. The service also provides an API for collected podcast data; API calls require a bearer token associated with a valid API key. OP3 describes its focus as open data and listener privacy. It stores basic request attributes and hashes and encrypts listener IP addresses before storage. It says it does not join IP addresses with third-party data or services, and its privacy policy says it uses no cookies. Cloudflare is identified as its sole hosting provider and data store. The setup guide names Megaphone, Transistor, and Castopod as hosting services that support custom prefixes. API hit-query results can be filtered by URL or hashed IP address only for the last 90 days. OP3 says its redirect service runs on a global CDN with edge nodes in more than 335 cities across more than 125 countries. The independent project is by John Spurlock; its terms identify SKYMETHOD LLC as doing business as OP3.
For and against
For
- Public stats pages include download metrics and breakdowns.
- Spreadsheet exports cover the full history.
- No signup or login is required.
- The privacy policy says OP3 uses no cookies.
- Megaphone, Transistor, and Castopod support custom prefixes.
Against
- API calls require a bearer token tied to a valid key.
- Hit-query filters cover only the last 90 days.
The verdict
OP3 offers podcast download analytics through a feed URL prefix, with public statistics and an API. Its hit-query filtering is limited to the most recent 90 days.
Who it suits
OP3 is intended for podcasters and podcast hosting companies that want download metrics from episode URLs. It may also suit users who want public show statistics and spreadsheet exports.
Plans and prices
Free
No signup or login required · public stats page · download metrics · spreadsheet exports
Read 15 Oct 2026 · op3.dev
OP3 Sponsorship
Sponsorship to help fund development
Read 8 Oct 2026 · github.com
On the record
- API
- The OP3 API provides access to collected podcast data, and API calls require a bearer token associated with a valid API key.op3.dev · read 8 Oct 2026
- API capabilities
- Documented API resources include raw hits, show information, episode download counts, transcript queries, top-app queries and monthly or weekly download queries.op3.dev · read 15 Oct 2026
- API endpoint
- The public API uses https://op3.dev/api/1 and requires a bearer token associated with an API key.op3.dev · read 15 Oct 2026
- API formats
- The hits endpoint documents TSV plus three JSON output formats: object-based JSON, array-based JSON and the default TSV.op3.dev · read 15 Oct 2026
- API specification
- The API documentation offers a downloadable OpenAPI specification and identifies the API license as MIT.op3.dev · read 15 Oct 2026
- Audience
- The project describes its intended users as podcasters and podcast hosting companies.op3.dev · read 8 Oct 2026
- Changelog
- A release dated August 7, 2025 added an API query for episode download counts.op3.dev · read 15 Oct 2026
- Cookies
- The privacy policy states that OP3's website uses no cookies.op3.dev · read 15 Oct 2026
- Download caveat
- OP3 states that a download is an upper-bound server request measure and does not necessarily equal an actual listen.op3.dev · read 15 Oct 2026
- Download filtering
- OP3 ignores non-GET requests, very small range requests, duplicate requests within 24 hours and identified bots or preloaders when calculating downloads.op3.dev · read 15 Oct 2026
- Global delivery
- OP3 says it runs on a global CDN with edge nodes in more than 335 cities across over 125 countries.op3.dev · read 15 Oct 2026
- Hosting
- The privacy policy identifies Cloudflare as the sole hosting provider and data store.op3.dev · read 8 Oct 2026
- Hosting architecture
- OP3 says its production services are automatically deployed to Cloudflare, which acts as the sole hosting provider and data store.op3.dev · read 15 Oct 2026
- How it works
- Podcasters or hosting companies add https://op3.dev/e/ before episode URLs in their podcast feed to measure downloads.op3.dev · read 8 Oct 2026
- Integrations
- The setup page specifically mentions Megaphone, Transistor and Castopod as hosts that can add OP3 through dashboard settings or support.op3.dev · read 15 Oct 2026
- Legal entity
- The terms identify SKYMETHOD LLC as doing business as OP3.op3.dev · read 8 Oct 2026
- Limit: IAB certification
- A Reddit reviewer said OP3 was not IAB certified despite finding its numbers similar to several other measurement systems.reddit.com · read 15 Oct 2026
- Limit: interface
- The Podosphere characterized OP3's user interface as minimal and aimed at technical users comfortable with raw data.thepodosphere.com · read 15 Oct 2026
