Audit & compress every image on any page
CompressFile — Image Audit scans a page, tells you exactly which images to resize, convert, or re-compress with the bytes each fix saves, and re-encodes the ones you pick — entirely on-device.
Free · No account · No API key · Nothing uploaded
CompressFile — Image Audit
On-device. Nothing is uploaded.
- Oversized−1.8 MB
hero.jpg — displayed 640×360, file is 3840×2160. Resize to 1280×720.
- Wrong format−1.2 MB
product.png — photographic PNG → convert to WebP.
- Under-compressed−612 KB
banner.jpg — 0.71 bytes/pixel → re-encode at quality 80.
What it does
Scans the whole page
Every <img>, srcset, CSS background, shadow-DOM image, favicon, and iframe — not just what you can see.
Quantified findings
"Resize to 800×600, saves 412 KB." "Convert PNG → WebP, saves 1.2 MB." Concrete numbers, not vague advice.
One-click compress
Select the fixes you want and download a ZIP of re-encoded images, with a before/after report included.
100% on-device
Same client-side engine as the website. Images never leave your machine — verifiable in DevTools' network tab.
Every modern format
Re-encodes to JPEG, PNG, WebP, and AVIF (AVIF on Chrome 121+), using the same wasm codecs as Squoosh.
Honest by design
Every reported saving is measured by a trial encode, and nothing that came out larger is ever handed back.
How it works
Open the side panel
Click the toolbar icon on any page. The scanner injects on demand — no broad permissions at install.
Review the findings
See total page image weight, the possible saving, and a ranked list of fixes with exact byte counts.
Compress & download
Tick the images you want, hit the button, and get a ZIP of optimized files plus a savings report.
Private by architecture, not by promise
The extension bundles its image codecs as WebAssembly and runs them in your browser. No image bytes are ever sent to a server — there is no server. That's not a policy you have to trust; it's something you can verify by opening the DevTools network tab while it works, or by running it with your connection switched off.
This matters more for automated tools than manual ones: when you let something batch-process a page's images, you don't want that to mean silently uploading them. Local processing removes the question entirely — the same principle behind the compressor and the client-side vs server-side comparison.
Frequently Asked Questions
Does it upload my images anywhere?
No. All scanning, analysis, and re-encoding happen locally in your browser using bundled WebAssembly codecs. You can confirm it by watching the DevTools network tab — nothing is transmitted.
What permissions does it need?
At install it only asks for activeTab — it can read images from a page just for the tab you explicitly act on. To read images hosted on other domains (CDNs) with byte-accurate savings, it requests broader access at runtime, behind an explicit button.
How is this different from the website?
The website compresses images you upload from your device. The extension audits images that are already live on a page — finding oversized, wrong-format, and under-compressed images automatically, then fixing the ones you pick.
Which browsers are supported?
Chrome and Chromium-based browsers (Edge, Brave, Arc) version 116+. AVIF output additionally requires Chrome 121+.
Is it free?
Yes. Like the website, it's free with no account, no API key, and no limits.