Image Load Lab

Editorial Policy

How a guide goes from question to published number, the rules every guide follows, sources, image credits, independence and corrections.

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Image Load Lab publishes test results that help readers decide how to encode, size and load images. This page explains how a guide gets from a question to a published number, and the rules every guide follows.

From question to published guide

  1. Question. Each guide answers one practical question, such as “how much smaller is AVIF than JPEG at the same visual quality?”.
  2. Test design. We choose the images, settings and number of repeats before looking at results, following the testing methodology.
  3. Run. Scripts run on the test bench described on the About page. The raw output (one row per file or per page load) is saved as CSV.
  4. Write-up. Tables and charts are generated from that CSV. Numbers in the text are copied from the same data, and each guide links the CSV so readers can check them.
  5. Limits. Every guide states what the test cannot show and which images or conditions were exceptions.
  6. Updates. When software versions change or a reader reports a result that does not reproduce, the guide is re-tested or corrected, and the changelog records what changed.

Rules for every guide

  • No number is published unless it comes from a run on our bench, and the CSV behind it is linked.
  • No invented quotes, testimonials, credentials or personal anecdotes.
  • No stock photos. Photos come from Wikimedia Commons under CC0 or public-domain terms and are credited; other images are either screenshots of real software or charts and fixtures generated by our scripts, and they are labelled that way.
  • Statements about how browsers or WordPress behave either link to primary documentation or to our own measurement.

Sources and images

We link to primary references (MDN, web.dev, the HTML specification, WordPress developer documentation, libjxl and libwebp documentation) rather than to other blogs. Every photograph’s author, licence and original URL is listed on the image credits page.

Independence

We do not accept payment for coverage and we do not publish sponsored results. When a guide mentions a product, library or service, the mention is based on a test we ran. The site may show advertising; advertisers have no influence over which topics are tested or what the results say.

Corrections

Send the page URL, the claim you believe is wrong and, ideally, your own measurement through the contact page. We re-run the affected test, correct the page if needed, and note the correction in the changelog.