OnlyJPG: Private browser-based converter for any image format to JPG.

What it does

OnlyJPG is a browser-based image converter that transforms various image formats into JPG files. The tool runs entirely locally in the browser with no server uploads. It supports conversion from PNG, WebP, AVIF, HEIC, PDF, SVG, TIFF, TGA and other formats. The underlying engine uses Google's Jpegli codec running in WebAssembly, enabling perceptual color quantization by default.

Who it is for

The tool targets users who need to convert images to JPG format but want to keep files private and avoid uploading to cloud services. It appeals to photographers, graphic designers, and anyone handling sensitive image files who prefer local processing. Users concerned about privacy or working offline benefit from the in-browser architecture.

Pricing

The site does not show prices. The tool is offered as free software.

How it stands out

OnlyJPG differentiates itself through local processing that avoids any file uploads. Most image converters operate as web services requiring cloud transmission. The tool offers granular control over output settings: multiple presets tailored to use cases (web, archival, screenshots, maximum compression), quality controls using perceptual distance rather than percentages, chroma subsampling options, and the ability to measure output quality via PSNR and SSIM metrics. The implementation of Jpegli with XYB color quantization and progressive JPEG support suggests technical sophistication in image encoding decisions.

What a founder should check

A builder considering a similar product should verify the competitive landscape. Numerous free online converters exist (CloudConvert, Zamzar, XConvert), though most require uploads. Desktop solutions like Adobe products and ImageMagick offer local conversion but target different user segments.

Second, investigate switching costs and user lock-in. For a free, no-account tool, switching costs are minimal. Users can easily try competitors. Success depends entirely on the tool being faster, more private, or offering better output quality than alternatives.

Third, examine the technical moat. The Jpegli implementation and perceptual encoding appear sophisticated, but WebAssembly-based image processing is increasingly accessible. The advantage diminishes if browser vendors improve native codec support or if competitors adopt similar libraries. The real moat may be simplicity of interface and preset design rather than underlying technology.

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