PhotoFilter is a one-job website: a photo editor where every adjustment is honest math you can inspect, running entirely on your own machine.

Honest editing, on purpose

Two things about typical online photo tools bothered us enough to build this. The first is the upload step — your photo travels to someone’s server, gets filtered there, and comes back, which is a strange way to process a file your browser can handle itself. The second is the mystery slider: tools show you a preview that may or may not match what downloads, powered by parameters they don’t disclose.

So this editor works differently in both directions. The processing is plain JavaScript running in your tab — decoding, per-pixel adjustments, re-encoding, no server involved. And the math is published: the slider math page lists every formula in pipeline order, and each preset on the home page shows its exact recipe instead of a name and a promise. When you tap Graphite, you watch the saturation slider fall to −100 — that’s the entire trick.

A quick tour

• The editor — ten sliders (exposure, brightness, contrast, highlights, shadows, warmth, saturation, sharpen, vignette, grain), nine named presets, a before/after split view, undo/redo, zoom to 200%, and batch editing for up to eight photos.
• Slider math — the formulas, honestly derived, in the order they run.
• Which slider — problem-first: dark, flat, cold or soft photo → the adjustment that actually fixes it.
• Workflow — a five-pass editing order that avoids rework.
• JPEG or PNG — which export format for which job.

Built without a backend

The site is static files served from Cloudflare’s edge — there is no image server to leak or to break, which is a privacy feature as much as an architecture choice. The filtering code is a few hundred lines of dependency-free JavaScript; view source and it’s all there. PhotoFilter is run by a small independent team that builds focused utility sites. It isn’t affiliated with any camera maker, app or platform — and the preset names are our own, not borrowed from any photo app.

Something rendering wrong, a formula that doesn’t check out, a preset that should exist? Write to us — corrections jump the queue.