JPEG uses lossy compression, so every reduction involves a quality trade-off. Our tool finds the optimal balance automatically.
Upload Your JPG Photos
Drag and drop JPG or JPEG files into the upload area. Works with camera photos, screenshots, and edited images. Batch upload is supported.
Set the Quality-Size Balance
Pick a target file size from the dropdown. The engine adjusts JPEG quality factor (1-100) to hit your target while minimizing visible artifacts like banding or blockiness.
Download Compressed JPGs
Download individually or as a ZIP. EXIF metadata (camera model, GPS, date) is stripped during compression to further reduce size and protect your privacy.
Why Choose Our JPG Compressor
Lossy Compression
JPEG's DCT-based lossy compression discards high-frequency detail the human eye barely notices, achieving 60-70% smaller files at quality 80-85.
Small File Size
Chroma subsampling stores color at half the resolution of brightness, cutting file size by a third with almost no visible difference in photographs.
Universal Support
JPG is the most widely used image format on the web. Every browser, device, email client, and social media platform supports it natively.
Progressive Loading
Progressive JPEGs render a blurry preview first, then sharpen as data arrives. They are slightly smaller than baseline JPEGs and feel faster on slow connections.
Ideal for Photographs
JPG excels at photographs, product images, social media posts, blog hero images, and any image with millions of colors and smooth tonal transitions.
Metadata Stripping
EXIF data like camera model, GPS coordinates, and timestamps are removed during compression, reducing file size and protecting your privacy.
圧縮の物理学
How JPG compression works at this target
JPG uses lossy DCT compression tuned by a single quality parameter (0-100). A stock 3 MB smartphone JPG typically starts at quality 92. Reaching a small size target means dropping quality, and the relationship is non-linear: the first 40% size cut is nearly invisible (quality 92 → 80); the last 40% is where visible artefacts appear — mostly ringing near sharp edges (text, faces at close crop), colour banding in blue skies, and blockiness in flat backgrounds. Our compressor iterates quality downward until the size cap is met, so photos with lots of flat area hit the target at higher quality than detail-heavy ones.
サイズ目標にマッピングされた実際のポータル
Which target size to pick for JPG
Different portals cap JPG uploads at different sizes. Pick the target that matches where you’re uploading rather than shrinking blindly — over-compressing wastes visible quality, under-compressing gets rejected.
Quick answers about compression targets, upload limits, format behavior, and the best cases for compressing JPG files.
How do I compress JPG files online?
Choose a target size, upload your JPG file, and click Compress. iFormat shrinks it to your chosen size while keeping quality as high as possible — free, no watermark, and no account needed.
JPG compression works by adjusting the quality parameter (1–100) that controls how aggressively the DCT algorithm discards high-frequency color information. At quality 85, most photos lose no visible detail. At quality 60, you may notice softening in fine textures and gradients. The compressor iteratively adjusts this parameter until the file hits your target size.
Will compressing reduce JPG quality?
JPG compression is lossy — it discards color data the human eye is least sensitive to. At moderate compression (quality 70–85), the difference is invisible at normal viewing distances. Below quality 50, blocking artifacts and color banding become noticeable, especially in smooth gradients and skin tones.
Is the JPG compressor free?
Yes. Compressing JPG files is free with no watermark and no sign-up. Paid plans only raise file-size and batch limits.
The compressor preserves EXIF metadata (camera model, date, GPS) by default. EXIF data is typically 5–50 KB, so stripping it alone rarely achieves a meaningful size reduction compared to quality adjustment.
What is the smallest size a JPG can be compressed to?
It depends on image dimensions. A 4000×3000 photo can rarely go below 50 KB without severe artifacts. If you need an extremely small file, reducing image dimensions (e.g., to 1024×768) before compressing dramatically lowers the floor.
Related Guides for JPG Compressor
Read file-size, upload, and quality guidance related to compressing JPG files.
