What is Schema Source by Tabstack?

Schema Source is a free tool that generates a JSON Schema for any URL you provide. Paste a link, and it returns a ready-to-use schema as JSON Schema, a Zod object, or a Pydantic model—perfect for copying directly into your extraction or validation code. It learns each site's URL patterns, so results are fast and consistent across pages with the same structure. Every generated schema also acts as an API: request the same URL with JSON content negotiation and get the cached schema back, no key required. Built by the team behind Tabstack and backed by Mozilla.

Who it's for

• Developers who need to quickly extract structured data from web pages without manually writing schemas.
• Data engineers working with scraping pipelines that require consistent, reusable schema definitions across multiple pages of the same site.
• API consumers who want to validate or transform web content using standard formats like JSON Schema, Zod, or Pydantic models.

Key features

Multi-format output

Schema Source delivers schemas in three formats: JSON Schema, Zod, and Pydantic models. You can copy the output directly into your extraction or validation code, saving time on manual schema creation.

URL pattern learning

The tool automatically learns each site's URL patterns, so results for pages like reddit.com/r/[subreddit-name] or zillow.com/homedetails/[address-slug]/[zpid]/ come back fast and stay consistent across pages of the same shape.

API access without keys

Every generated schema is also an API endpoint. Request the same URL with JSON content negotiation and get the cached schema back—no API key required. This makes it easy to integrate into automated workflows.

What stands out

"Paste a link, get a schema—no key, no setup, just code you can use."

This one-liner captures the product's core edge: zero friction from URL to usable schema. Unlike other tools that require registration, API keys, or manual configuration, Schema Source delivers instant, copy-ready output. The fact that it's free and backed by Mozilla adds credibility, while the API access feature means you can automate schema retrieval without managing credentials.

Worth checking out if…

You're a developer or data engineer who regularly extracts data from websites and wants to skip the manual schema-writing step. If you work with scraping tools, validation pipelines, or any project that needs structured data from URLs, Schema Source offers a fast, free, and format-flexible solution. It's especially useful for sites with consistent URL patterns like Reddit, Zillow, Amazon, or Product Hunt.