Add new spec: WebAssembly Core 3.0

[chrisdavidmills]

URL

https://webassembly.github.io/spec/core/

Rationale

I'm currently working on documenting WebAssembly — the whole core language, not just the JS API — and I'd like to be able to provide specific spec refs for individual instructions, etc. So it'd be great to get this spec added.

Additional properties

{}

[browser-specs-bot]

Changes to index.json

This update would trigger the following changes in index.json:

Add spec (1)

{
  "url": "https://webassembly.github.io/spec/core/",
  "seriesComposition": "full",
  "shortname": "spec",
  "series": {
    "shortname": "spec",
    "currentSpecification": "spec",
    "title": "WebAssembly Specification¶",
    "shortTitle": "WebAssembly Specification¶",
    "nightlyUrl": "https://webassembly.github.io/spec/core/"
  },
  "organization": "W3C",
  "groups": [
    {
      "name": "WebAssembly Community Group",
      "url": "https://www.w3.org/community/webassembly/"
    }
  ],
  "nightly": {
    "url": "https://webassembly.github.io/spec/core/",
    "status": "Editor's Draft",
    "alternateUrls": [],
    "repository": "https://github.com/WebAssembly/spec",
    "filename": "index.html"
  },
  "title": "WebAssembly Specification¶",
  "source": "spec",
  "shortTitle": "WebAssembly Specification¶",
  "categories": [
    "browser"
  ],
  "standing": "good"
}

Tests

With these changes, the following tests would fail:

The `index.json` list contains relative paths to source of nightly spec when repository is known

Expected:

[]

Actual:

[
  {
    "url": "https://webassembly.github.io/spec/core/",
    "seriesComposition": "full",
    "shortname": "spec",
    "series": {
      "shortname": "spec",
      "currentSpecification": "spec",
      "title": "WebAssembly Specification¶",
      "shortTitle": "WebAssembly Specification¶",
      "nightlyUrl": "https://webassembly.github.io/spec/core/"
    },
    "organization": "W3C",
    "groups": [
      {
        "name": "WebAssembly Community Group",
        "url": "https://www.w3.org/community/webassembly/"
      }
    ],
    "nightly": {
      "url": "https://webassembly.github.io/spec/core/",
      "status": "Editor's Draft",
      "alternateUrls": [],
      "repository": "https://github.com/WebAssembly/spec",
      "filename": "index.html"
    },
    "title": "WebAssembly Specification¶",
    "source": "spec",
    "shortTitle": "WebAssembly Specification¶",
    "categories": [
      "browser"
    ],
    "standing": "good"
  }
]

Crawl results for WebAssembly Specification — WebAssembly 3.0 (2026-04-20)

Crawl summary:

• Title: WebAssembly Specification — WebAssembly 3.0 (2026-04-20)
• Date: 20 April 2026
• Canonical URL: https://webassembly.github.io/spec/core/
• Spec defines:
  • Headings: 1 found
  • IDs: 8 found
  • Links: 2 rawlinks
• No Algorithms, CDDL, CSS, Events, References, Terms, Web IDL definitions found

[tidoust]

Do you need to use that specific URL?

The spec is already in the list through its Bikeshed rendition: https://webassembly.github.io/spec/core/bikeshed/

We could perhaps add https://webassembly.github.io/spec/core/ to alternateUrls if you need to use that. (If we do that, we should probably take the same approach for the ~15 WASM entries in the list)

[chrisdavidmills]

Ah, I didn't realize we had a bikeshed version already referenced, sorry, @tidoust. Yeah, I'll use that. I'm getting confused with all the different representations. This version is more easily searchable than the one I'm referencing, too.