Reduce JPEG file size by 40–80% without visible quality loss. Browser-based compression that runs entirely on your device — no files are ever uploaded, no account needed, no limits.
Quality slider, Target KB mode, batch support — everything in your browser, nothing uploaded.
When you take a photo on an iPhone, Samsung, or any DSLR, the camera saves the JPEG at a quality setting of 92–98%. That sounds sensible — you want to preserve the shot. But for web delivery, email, or social media, quality 95 and quality 78 look identical on a screen. The camera has no way to know how you'll use the photo, so it plays it safe and saves every detail.
There's a second factor: EXIF metadata. Every JPEG from a modern smartphone contains a hidden data block recording GPS coordinates, the exact camera model, lens focal length, aperture, ISO, shutter speed, capture date and time, and often a full-resolution embedded thumbnail of the image itself. This metadata can be 50–300 KB per file — a meaningful chunk when you're trying to get an image below 200 KB for a web page.
When you run a JPEG through a browser-based compressor, both problems are solved in one step: the image is re-encoded at an appropriate quality level, and the entire EXIF block is stripped in the process. That's why compressed files are often far smaller than you'd expect — you're not just compressing, you're also dropping the metadata overhead entirely.
The quality slider goes from 1 to 100, but most of that range is useless in practice. Almost no real-world use case benefits from settings above 90 — the files are massive and the quality gain is invisible to humans. Here's what each range actually delivers:
| Quality Range | Visual Result | Typical Reduction | Best For |
|---|---|---|---|
| 90–100% | Near-perfect | 5–25% smaller | Print, professional archiving — rarely needed for web |
| 83–89% | Excellent | 35–50% smaller | E-commerce product photos, portfolio work, hero images |
| 75–82% | Very good | 50–65% smaller | Most web images, blog photos, landing pages — default sweet spot |
| 65–74% | Good | 60–72% smaller | Thumbnails, previews, images displayed at small sizes |
| 55–64% | Acceptable | 68–78% smaller | Background images, low-priority images below the fold |
| 40–54% | Visible artifacts | 75–85% smaller | Rarely — only if extreme size constraint with no quality bar |
| Below 40% | Severe degradation | 80–92% smaller | Not recommended for any user-facing image |
The practical takeaway: start at quality 75 and only adjust from there. If you're compressing product photos that buyers zoom into, bump to 83–85. If you're compressing a row of 200px thumbnails, 68–72 is perfectly fine. The default setting of 75 hits the sweet spot for the vast majority of web images.
JPEG compression works by dividing the image into 8×8 pixel blocks, applying a Discrete Cosine Transform to each block, and then throwing away the coefficients that carry the least visual information. At high quality settings, this process is imperceptible. At lower settings, the blocks become visible and you see characteristic "JPEG artifacts."
The 8×8 pixel grid becomes visible as hard-edged squares, especially in smooth gradient areas like sky or skin. Appears at quality settings below 60. Most visible in high-contrast areas near edges.
Halo-like patterns around sharp edges — text, logos, and high-contrast lines. Particularly bad when compressing images that contain text or have screenshots embedded in them.
Smooth color gradients get divided into visible steps or bands rather than blending continuously. Common in sky photos and gradients at quality settings below 65.
Fine texture detail (fabric, hair, grass) blurs together into a smooth, paint-like appearance. The compression can't distinguish between meaningful texture and "noise to discard."
Go to convertlo.pro/compress.html. The tool runs entirely in your browser — no software to install.
Drag and drop one file or an entire folder. JPEG, JPG, JFIF, and JFIF-EXIF variants all work. No file count limit.
Use the quality slider (default 75 is the sweet spot) or switch to Target KB mode to specify an exact output size — useful for email or social media limits.
Hover any image in the grid to see a side-by-side comparison. If the quality looks off, drag the slider higher and re-compress.
Click a card to download individually, or hit "Download All" for a ZIP of every compressed file at once.
For web delivery, converting to WebP after compression adds another 25–35% reduction. Use the JPG→WebP converter for the second step.
JPEG compression is lossy and works by discarding pixel data. PNG compression is lossless and only removes redundant data. Whether to use JPEG depends entirely on your image content:
Photos of people, places, products, food, events. JPEG handles continuous tonal gradients and complex textures well. Quality 75–85 is undetectable from the original for photo content.
Any image with sharp edges, flat colors, text, or transparency. JPEG introduces ringing artifacts around every sharp edge. PNG compresses these losslessly — same quality, just smaller.
If you're publishing to a website and can serve WebP, skip JPEG compression entirely. WebP achieves 25–35% better compression than JPEG at the same visual quality — the superior choice for web delivery.
Each JPEG re-compression cycle introduces new quality loss on top of the existing degradation. If you already compressed a JPEG at quality 70, re-compressing at 70 again doesn't give you quality 70 twice — it gives you progressively worse quality each pass.
Every platform has different constraints. Here's the practical guide for the most common ones:
| Platform / Use Case | Recommended Quality | Target Size | Notes |
|---|---|---|---|
| Website / Blog | 75–80% | <200 KB per image | Hero can go to 300–400 KB if preloaded; thumbnails target 40–80 KB |
| E-commerce product | 83–88% | 150–400 KB | Buyers zoom in — higher quality justified; use Target KB for large catalogs |
| Email inline image | Target KB mode | 100–400 KB | WebP not supported in email; JPEG only. Target 300 KB for reliable delivery |
| Instagram feed post | 82–88% | <8 MB (their limit) | Instagram re-compresses on upload; pre-compress to 1–2 MB to control quality |
| Twitter/X | 80–85% | <5 MB | Twitter also re-compresses; 1080px wide, <2 MB for best feed quality |
| 80–85% | <8 MB | Pre-compress to 1–3 MB so LinkedIn's re-encode doesn't degrade it visibly | |
| WordPress media library | 78–83% | <500 KB | WordPress does its own re-encode at 82%; pre-compressing at 78–80 prevents double-loss |
| Print / archiving | 90–95% | Whatever results | Don't heavily compress images intended for print — use lossless or high quality |
For the maximum file size reduction on web images, combine JPEG compression with WebP conversion. The two steps work on different aspects of the file and the savings stack additively — not redundantly.
Step 1: Compress the JPG at quality 78–82. This strips EXIF metadata and reduces the quality to web-appropriate levels. A 3 MB photo typically becomes 400–600 KB.
Step 2: Convert the compressed JPEG to WebP using the JPG→WebP converter. WebP's encoder is inherently more efficient than JPEG's — it achieves another 25–35% reduction on the already-compressed file at the same perceptual quality.
Result: A 3 MB original JPEG typically ends up at 280–420 KB WebP — an 86–91% total reduction from the original, with no perceptible quality difference in a browser at normal zoom.