How to Convert a Photo to Black and White
Black and white never goes out of style: it strips away distracting color casts, adds drama to portraits, and gives street photography that timeless feel. Most people reach for a heavy photo editor for a one-click grayscale — overkill. Re-Sizefy applies a proper luminance-based grayscale filter (not a naive average, so skin tones stay natural) to one photo or a whole batch, right in your browser, with nothing uploaded.
Step-by-step: go black and white
- Drop in your photos. One or a whole batch — portraits, street shots, landscapes all work.
- Enable the grayscale filter. One toggle converts the full-color image using luminance weighting (29.9% red, 58.7% green, 11.4% blue), which matches how human eyes perceive brightness — far more natural than a flat average.
- Add contrast for punch. Black-and-white lives on tonal contrast. Nudge the contrast slider up 10–20 points; flat color photos often need it once the color is gone. Check the live preview.
- Choose your output format. JPG at quality 85 for sharing and printing; WebP at 80 for web use. Grayscale images compress especially well, so files stay small.
- Download. Single files download directly; batches arrive as one ZIP. Your originals are untouched — the tool only exports new copies.
Quality tips
Not every photo improves in black and white. Look for strong light-and-shadow, interesting textures, and bold shapes — a photo that relied on color alone (a sunset, autumn leaves) often falls flat without it.
Portraits usually want slightly less contrast than landscapes in B&W: too much contrast turns skin blotchy, while a gentler curve keeps it flattering.
Try the negative filter too — inverted black-and-white has a striking x-ray aesthetic that works beautifully for architecture and high-contrast graphic shots.
Things to watch out for
- Originals are never modified. The grayscale applies to the exported copy only — but that also means if you close the tab without downloading, the conversion is gone. Download before you leave.
- Do not double-convert. Converting an already-grayscale JPG to black and white again just re-compresses it. Always work from the color original.
- Check skin tones. Luminance grayscale is flattering, but very warm indoor lighting can render skin darker than expected — a small brightness bump (+5–10) compensates.
Try it now
Open the free Re-Sizefy converter — drop in your photo, toggle grayscale, download timeless black and white. No sign-up, no upload.
Frequently asked questions
Does black-and-white conversion reduce quality?
No more than any export — use quality 85+ and the only change is the absence of color. The original file is never touched.
What is luminance grayscale?
A conversion weighted by how eyes perceive brightness (mostly green, then red, then blue), producing natural tones — unlike a naive average that makes skin look muddy.
Can I convert many photos to black and white at once?
Yes. Batch mode applies the grayscale filter and your contrast tweak to every photo, delivering one ZIP.
Can I undo it later?
Your original stays intact — only the downloaded copy is black and white. Re-export from the original any time.