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Compress JPG

Reduce JPEG file size by up to 80% without visible quality loss. Adjust quality, optionally resize, and download instantly. 100% free — your images never leave your browser.

How JPEG compression works

JPEG compression works by dividing the image into 8×8 pixel blocks and discarding frequency information that the human visual system is least sensitive to. At quality 85, approximately 5% of the original data is discarded — but this 5% is specifically chosen to be the information your eye is least likely to notice. The result is a file roughly 3–5x smaller with almost no perceptible quality difference.

What quality setting should I use?

  • Quality 85–90: Professional quality. Suitable for print-ready web images and product photography.
  • Quality 75–85: Standard web quality. The sweet spot for most websites — smaller than 90 with no visible artifacts at normal viewing sizes.
  • Quality 60–75: Aggressive compression. Good for thumbnails, background images, or anywhere file size matters more than quality.
  • Quality 40–60: Maximum compression. Visible artifacts appear. Use only for very small thumbnails.

JPG vs WebP: which is smaller?

For equivalent quality, WebP produces files 25–35% smaller than JPEG. If your site supports WebP (all modern browsers do), converting to WebP instead of compressing JPG gives you better results. Use the JPG to WebP converter → for this.

Frequently asked questions

Compressing JPG (reducing quality) keeps the JPEG format but makes the file smaller. Converting to WebP switches to a more efficient format that achieves 25–35% smaller files at equivalent quality. For web use, JPG-to-WebP gives better results. For email and non-web use where JPEG compatibility matters, compress the JPG directly.
Yes — JPEG is a lossy format, so every re-compression cycle introduces additional quality loss. This is called “generation loss.” To avoid this, always work from the original high-quality source and compress once for the intended use. Never compress, save, and re-compress the same JPEG multiple times.
Not with JPEG — it is inherently a lossy format. However, lossless JPEG optimization tools (like jpegtran) can remove metadata and optimize encoding tables without changing pixel data. For truly lossless compression, use PNG or WebP lossless mode instead.
For email attachments, target a final file size under 1 MB (most email services cap attachments at 10–25 MB, but large images slow email loading). Use quality 75–80 and resize the image to its display dimensions — there’s no need to attach a 4000×3000 photo if it will be displayed at 800×600. Quality 80 at 1200×900 pixels typically produces a 150–350 KB JPG, perfect for email.