How image compression works (and why it stays on your device)
SqueezeIMG uses your browser's built-in image codecs — the same encoders Chrome, Edge, Firefox and Safari use to render the web — to decode each picture onto an off-screen canvas and re-encode it at the quality you choose. Because the work happens in JavaScript inside your own tab, nothing is uploaded to any server. There is no queue, no per-file size limit, and no "free tier" counting your conversions. You can verify this yourself: load the page, switch off Wi-Fi, and compression keeps working.
Most images shrink dramatically because cameras and screenshots are saved far more conservatively than the web needs. A 12-megapixel phone photo is typically 3–5 MB, yet the largest version any website displays is usually under 400 KB. Two levers do the heavy lifting: re-encoding (modern formats like WebP and AVIF store the same visual detail in fewer bytes) and resizing (a 4000-pixel-wide photo shown in a 800-pixel column wastes ~96% of its pixels).
Which format should I pick?
| Format | Best for | Typical savings vs. original* | Browser support (2026) |
|---|---|---|---|
| WebP | Photos, screenshots, UI images — the safe default | 25–45% smaller than JPEG, 60–80% smaller than PNG photos | ~98% of browsers in use |
| AVIF | Hero images and photo-heavy pages where every KB counts | 40–60% smaller than JPEG at similar quality | ~94% of browsers; canvas encoding only in Chromium-based browsers |
| JPEG | Maximum compatibility (old email clients, legacy CMSs) | 30–70% smaller than camera originals at quality 80 | Universal |
| PNG | Logos, line art, images that must stay pixel-perfect | Varies — lossless; resize is where PNG savings come from | Universal |
*Savings are estimates based on typical photographic content at quality 80 in 2026-era browser encoders; your results depend on image content, dimensions and the quality slider.
Recommended settings by use case
- Website images: WebP, quality 80, max width 1920 px (or 1600 px for blog content). Aim for under 200 KB per image.
- Email attachments: JPEG, quality 75, max width 1280 px — keeps a 20-photo batch under most 25 MB inbox limits.
- Social media: JPEG or WebP, quality 85, max width 1080 px — platforms re-compress anyway, so don't ship more pixels than they keep.
- Archiving with privacy: any format with Strip metadata on — removes GPS coordinates, camera serial numbers and timestamps embedded by phones.
Compress to an exact file size
Switch Compression mode to Target file size when you have a hard ceiling to hit — an email gateway that rejects attachments over 10 MB, a marketplace that caps listing photos at 200 KB, or a CMS that wants hero images under 150 KB. Instead of guessing at the quality slider, you pick the size and SqueezeIMG re-encodes each image a handful of times, narrowing in on the highest quality that still fits. Every image in the batch is tuned independently, so a flat graphic and a busy photograph both land just under your number — no manual trial and error.
One-click presets for every destination
The four built-in presets — Web (WebP, quality 82, 1920 px), Email (JPEG, quality 78, 1280 px), Social (JPEG, quality 85, 1080 px) and Smallest (target 200 KB) — set the format, quality and resize width together so you don't have to memorise the recipe. They're free. With SqueezeIMG Pro you can also save your own named presets and reuse them across sessions, export a CSV report of an entire batch for your records, and add a filename prefix to keep exports organised.
SqueezeIMG is part of a family of privacy-first browser tools: cut out backgrounds with BG Remover, work with documents in PDFLocal, or caption pictures with Image Describer — and one AppVitamins pass unlocks the Pro extras across all of them.