Building PixelToKB: Browser-Based Image Tools for Exact File-Size Limits

I kept running into the same problem when preparing images for application forms and websites: the file had to be under a specific limit, but most tools only offered a quality slider. That meant exporting, checking the result, and repeating the process.

I built PixelToKB to make that workflow more direct.

What it does today

PixelToKB currently includes:

• JPEG, PNG, and WebP compression with 10, 20, 30, 50, and 100 KB presets
• a custom target-size field for other limits
• an actual-byte check on the generated file before download
• image resizing and cropping
• lossless PNG optimization
• file-size, pixel-dimension, aspect-ratio, transparency, PPI, and DPI inspection tools

There is no account requirement.

Local processing as a product boundary

Selected images are processed in the browser and are not uploaded to a PixelToKB server. This matters for ordinary product assets, screenshots, document scans, and other files that users may not want to send to a third-party image service.

This is a narrow technical claim rather than a general security promise: the tool controls its own application flow, but it cannot make guarantees about a user's device, browser extensions, or network environment.

Why the byte check matters

A quality value is only an encoder input. It does not tell you the final file size.

PixelToKB checks the generated output itself and reports its actual byte count. If the selected format, dimensions, and target cannot produce a suitable result, the tool reports that instead of presenting an oversized file as successful.

This is useful for two common cases:

1. forms that enforce a strict upload limit;
2. web projects that need predictable image budgets for cards, thumbnails, or hero images.

Current limits

Very small targets may require lower quality or smaller dimensions, and browser encoders can produce different results across formats. Lossless PNG optimization is also different from lossy JPEG or WebP compression, so not every image can reach every target without changing its dimensions or format.

The goal is to make those constraints visible rather than hide them behind a single quality percentage.

Planned work

The next features on the roadmap are:

• signature-background cleanup;
• photo-and-signature composition;
• A4 and Letter print sheets;
• controlled enlargement for small images;
• additional interface languages after review.

PixelToKB is available at https://www.pixeltokb.com/.

If you work with strict image-size limits, I would be interested in feedback on the preset/custom workflow, browser-specific edge cases, and any formats that are missing from your usual process.