About

This Image to JPG Converter is a high-precision, client-side tool designed for engineers, designers, and privacy-conscious users. Unlike server-based converters, this tool processes your data entirely within your browser's local memory using the HTML5 Canvas API. This ensures that your files never leave your device, guaranteeing 100% Privacy and zero latency.

We address the two primary challenges of JPEG conversion: Compression Artifacts and Transparency Flattening. Since the JPEG standard does not support the alpha channel (transparency), our engine allows you to manually define a Matte Color to fill transparent backgrounds, preventing the default (and often ugly) black fill. Furthermore, the integrated Split-View Visualizer provides real-time Before/After inspection, allowing you to fine-tune the quantization tables (via the Quality slider) to find the perfect balance between visual fidelity and file size.

Formulas

The compression efficiency is calculated by comparing the input octet stream size against the resultant blob size. The Compression Ratio R is defined as:

R = 1 - (Size output \div Size input) 1 \times 100 %

When flattening transparency, the resultant pixel color C_out is a linear interpolation between the source pixel C_src and the matte color C_matte, governed by the alpha channel α (normalized 0 to 1):

C out = C src \times α + C matte \times (1 - α)

Reference Data

Quality Setting (q)	Use Case	Est. Size Reduction	Artifact Visibility
90 - 100	Archival / Print	10% - 30%	None (Lossless-like)
75 - 85	High-Res Web	40% - 60%	Negligible
50 - 70	Standard Web / Email	70% - 85%	Minor Color Banding
30 - 49	Thumbnails / Previews	85% - 95%	Visible Ringing
0 - 29	Placeholder / Abstract	95% +	Severe Blockiness

Frequently Asked Questions

Yes. The HTML5 Canvas conversion process naturally strips non-visual metadata, including GPS coordinates, camera models, and shutter settings. The resulting JPEG contains only pixel data, ensuring your privacy.

The JPEG standard does not support an Alpha (transparency) channel. When a transparent image is converted, the "empty" pixels must be filled with a color. Most systems default to black (R:0, G:0, B:0). Use our "Matte Color" selector to choose White or a custom color instead.

Because processing happens in your browser's RAM, the limit depends on your device's available memory. Typically, images up to 50MB or 8000x8000 pixels are processed smoothly on modern desktops. Mobile devices may have lower limits.

No. The JPEG "Quality" (0-100) is a heuristic value used by the encoder to determine quantization tables. A quality of "80" in this tool might differ slightly in file size from "80" in Photoshop due to different encoding algorithms (e.g., Libjpeg vs. Browser Native).