Image to JPG
Upload any image and convert it to JPEG format with your chosen quality level.
Reviewed by the ToolNestr Editorial Team — July 2026
How JPEG conversion works
JPEG conversion re-encodes image data using lossy DCT (Discrete Cosine Transform) compression. The image is divided into 8×8 pixel blocks, converted from RGB to YCbCr color space, and each block is transformed into frequency coefficients. Quantization then discards less important high-frequency information — the quality slider controls how aggressively this is done.
JPEG does not support transparency, so any transparent areas in the source image are filled with white during conversion. The result is a much smaller file that maintains good visual quality at medium-to-high quality settings, making it the standard format for photographs on the web.
Worked example
What different JPEG quality settings mean
How quality settings affect visual fidelity and file size.
Photographer
Converts high-resolution RAW exports to JPEG for client proofs and online galleries with adjustable quality to balance size and fidelity.
Web Publisher
Converts PNG screenshots and icons to JPEG for blog posts and articles where smaller file sizes are needed for faster page loads.
Social Media User
Converts images to JPEG before uploading to platforms that prefer the format, reducing upload time and data usage.
Email Marketer
Converts newsletter images to JPEG at optimized quality levels to stay under email client attachment size limits.
| Quality setting | Use case | File size | Visual quality |
|---|---|---|---|
| 100% | Lab/archival use | Very large | Virtually lossless |
| 90-95% | Photo printing | Large | Excellent |
| 80-90% | Web publishing | Moderate | Very good |
| 70-80% | Social media | Small | Good |
| 60-75% | Email attachments | Very small | Acceptable |
| 40-60% | Thumbnails | Tiny | Fair |
How to use the Image to JPG Converter
Upload an image
Select any image — PNG, WebP, AVIF, BMP or other — from your device for conversion.
Adjust quality
Use the quality slider to balance file size against visual quality. The preview and file sizes update in real time.
Download JPG
Click download to save your image in JPEG format. Everything happens in your browser.
Tips for using JPEG format
JPEG does not support transparency
When converting images with transparency (like PNG logos), the transparent areas become white. If you need transparency, stick with PNG or WebP.
80% is the sweet spot
For most images, 80% quality provides indistinguishable visual quality from the original while cutting file size dramatically. Reserve 90-100% only for print or when maximum quality is critical.
Re-saving degrades quality
JPEG is a lossy format — each time you re-save, compression artifacts accumulate. Always convert from the original source file to avoid generational quality loss.
How JPEG compression works
JPEG compression works by dividing the image into 8x8 pixel blocks, converting each from RGB to YCbCr color space, applying a discrete cosine transform (DCT), and then quantizing the frequency coefficients. High-frequency detail that the human eye is less sensitive to is discarded first, which is why JPEG excels at compressing photographs with smooth gradients but creates visible artifacts around sharp edges and text.
Quality vs file size
The quality setting in JPEG (1-100) controls the quantization table used during compression. Higher quality preserves more frequency data, resulting in larger files. The relationship is exponential: reducing quality from 100 to 90 typically halves file size with no visible loss, while dropping from 50 to 40 saves much less but introduces noticeable artifacts.
When to use JPG vs PNG
Use JPEG for photographs, complex images with many colors and gradients, social media posts, email campaigns, and any scenario where small file size matters more than absolute fidelity. Use PNG for screenshots, logos, digital art with sharp edges, images with text, and any image requiring transparency or pixel-perfect reproduction.
EXIF data
EXIF (Exchangeable Image File Format) data includes camera settings, GPS coordinates, date taken, and more. When converting images using the Canvas API in a browser, EXIF data is not preserved. If keeping camera metadata is important, use a dedicated EXIF-preserving tool or desktop software.
Frequently asked questions
What is JPEG format?
JPEG (Joint Photographic Experts Group) is a widely-used lossy image format that achieves small file sizes by discarding some image data. It is the most common format for photographs on the web.
Does JPEG support transparency?
No. JPEG does not support transparency. When you convert a PNG with transparency to JPEG, the transparent areas will be filled with white by default.
What quality setting should I use?
80% is the recommended sweet spot for most web use. It provides excellent visual quality while significantly reducing file size. For prints, use 90-100%. For email, 60-75% is sufficient.
Why is my JPEG file smaller than the original PNG?
JPEG uses lossy compression, which makes file sizes much smaller than lossless PNG. This is expected — JPEG trades some quality for smaller file size.
Does converting to JPEG lose quality?
JPEG compression is lossy, so converting to JPEG always reduces quality slightly compared to the original lossless source. However, at high quality settings (90%+), the difference is barely noticeable.
What image formats can I convert to JPEG?
Any format your browser supports, including PNG, WebP, AVIF, BMP, GIF, and TIFF.
Is the conversion done on my device?
Yes. All conversion happens in your browser using the Canvas API. No data is uploaded to any server.
Can I convert back to PNG after JPEG?
Yes, but quality lost during JPEG compression cannot be recovered. Converting JPEG to PNG will preserve the existing compression artifacts.
What happens to EXIF data?
EXIF metadata (camera settings, GPS location, date) is not preserved during browser-based Canvas conversion. Use a dedicated EXIF-preserving tool if metadata matters.
When should I use JPEG instead of PNG?
Use JPEG for photographs, social media images, email attachments, and any image where small file size is more important than pixel-perfect accuracy. Use PNG for text, logos, and graphics requiring transparency.