About Image Load Lab
Who runs Image Load Lab, the pen name behind the guides, and the test bench every result comes from.
Image Load Lab is a small, independent test bench for one practical question: how do you deliver images that look right without sending more bytes than the page needs? Every guide on this site starts with a question, runs a test on the equipment described below, and publishes the numbers, the files and the scripts that produced them.
Who writes and runs the tests
Guides are written by Daniel Vega. Daniel Vega is the pen name used by the independent developer who owns and operates Image Load Lab. We do not claim professional certifications, employers or years of experience for that name; the work is meant to be judged on the evidence each guide publishes.
Every number published here comes from a run on the machine listed below, and the scripts and raw CSV files are available so anyone can repeat or challenge the result. See the editorial policy for the full rules.
The test bench
All experiments published since September 2026 were run on one desktop computer, starting on September 29, 2026. Each guide gives the date its tests were run, and when a version changes, the affected guide says so.
| Component | Version used |
|---|---|
| Operating system | Windows 11 Pro x64, build 10.0.26200 (10.0.26300 after a Windows update in October 2026) |
| Processor / memory | Intel Core i5-13400F (16 threads), 32 GB RAM |
| Browser | Google Chrome 153, 154 and 155 (it updated itself during the test series; each guide names the exact version), driven by Playwright 1.63.0 |
| Image pipeline | sharp 0.35.5 with libvips 8.18.7, MozJPEG (0826579), libwebp 1.6.0, libaom 3.15.1, libheif 1.23.5 |
| Command-line encoders | cwebp 1.6.0, avifenc 1.4.2 (aom 3.14.1), oxipng 10.2.1 |
| Quality metrics | SSIM (scikit-image 0.26.0), DSSIM 3.4.0, SSIMULACRA2 (libjxl 0.12.0) |
| Runtime | Node.js 24.19.0, Python 3.14.3 |
What the lab publishes
- Format and compression tests on a fixed corpus of 20 CC0 or public-domain photographs, four synthetic images and eight real screenshots of this site.
- Loading tests on local fixture pages served from the bench and loaded in Chrome with a throttled network, repeated several times and reported as medians.
- WordPress tests run on this WordPress site itself, such as uploading a photo and recording every file the server generates.
- Two browser tools, an image optimizer and a srcset builder, that run on your device without uploading your files.
How the tests are run, which thresholds are used and what they cannot show is explained once, on the testing methodology page. The photographs are credited on the image credits page.
Corrections
If a result does not reproduce on your machine, send the page URL, your environment and the command you ran through the contact page or to hello@imageloadlab.com. Confirmed errors are fixed in the guide and listed in the changelog.