tree: 2752127ef55b337c07490190a0e6d188883b0258 [path history] [tgz]
  1. caspian/
  2. imports/
  3. static/
  4. templates/
  6. jsconfig.json

SuperSize Tiger Viewer

Webapp for viewing .size and .sizediff files.

Hosted at:

Running a Local Instance

To run the viewer locally:

  1. Install Firebase CLI
  2. Run ./ --local

The WebAssembly files are fetched from the deployed instance if you have not built them locally. To build them, see caspian/

Note: index.html dropdowns are not populated when running locally due to CORS restrictions. We should fix this by having index.html use the JSON api to perform authenticated fetches, like viewer.html does.

Deployment Info

  1. Test your change on a staging instance (which also does not support authenticated fetches)

    ./ --staging
    • index.html dropdowns don't work due to CORS (same as for --local).
    • viewer.html authenticated fetches (?load_url= of non-chromium-binary-size-trybot-results URLs) do not work due to us being unable to allowlist the staging domain (which is random each time).
  2. Deploy to prod instance (see here for details on who has permissions).

    ./ --prod
  3. Test your changes on the newly deployed instance (use DevTools to force Service Worker caching to update).

Code Overview

The viewer has no server component beyond static file serving. .size files are parsed using WebAssembly (caspian/ directory). The .wasm module runs within a Web Worker in order to not block the browser's UI thread. Node information is sent to the main page via JSON on-demand (when tree nodes are expanded).

Code Style

Code should follow Chrome's styleguide where possible.


This uses JSON files to populate the dropdowns:

All .size files pointed to by this launcher are restricted to Googlers.


This is the main WebApp. It uses a Service Worker (sw.js) and an App Manifest (manifest.json) to be more slick (and work offline).

Type Checking

The TypeScript Compiler is used to check JavaScript syntax and JSDoc. This is manually invoked using:

python3 tools/binary_size/libsupersize/viewer/