Black & White and Sepia Converter
Convert photos to black and white using a proper perceptual luma conversion rather than a naive channel average — the difference shows up immediately in skies and skin tones. Sepia is here too, and both have a strength control so you can stop halfway for a desaturated look, plus a contrast adjustment that usually makes the difference between a flat conversion and a deliberate one. Batch mode; nothing uploaded.
Drop photos here
JPG / PNG / WebP · multiple allowed · output is JPG
How to convert a photo to black and white
- Drop the photos in.
- Leave the method on Rec. 709 luma unless you have a reason to want a flatter or brighter result.
- Add 10–20% contrast — most photographs need it after a greyscale conversion.
- Click Convert. Compare against the original before you commit; the difference between the three greyscale methods is easiest to judge on a photo with a lot of sky or a lot of skin.
Why the method matters
Human vision is roughly 21% sensitive to red, 72% to green, and 7% to blue. A conversion that averages the three channels equally therefore misrepresents brightness — a saturated blue sky comes out far too light, a red jumper far too dark, and the whole photo loses the tonal separation that made it work in colour. Rec. 709 luma applies those perceptual weights, which is why it is the standard in film, video, and every serious editor. Use average or lightness deliberately, for effect, not as a default.
Sepia, without the cliché
Sepia at full strength on a modern digital photo tends to look like a filter. At 40–60% strength with a little added contrast it reads as a warm tone rather than a costume — closer to what a real sepia-toned print looked like. If you want the aged-print effect properly, pair it with Add border in an off-white and a Polaroid bottom margin.
FAQ
Why do the greyscale methods give different results?
Luma (Rec. 709) weights green heavily and blue barely at all, matching how the eye perceives brightness — it is the right default and what film and video use. Average treats the channels equally, which makes blue skies unnaturally bright and reds too dark, but occasionally suits graphics. Lightness takes the midpoint of the brightest and darkest channel, giving a flatter, lower-contrast result some people prefer for portraits.
What is the strength slider for?
It blends between the original and the converted version. At 1.0 you get full black and white; at 0.6 you get a desaturated look that keeps a hint of the original colour, which is a common editorial style. It is also how you make a subtle sepia rather than a heavy one.
Does black and white make the file smaller?
A little — usually 10–25% — because the chroma channels compress to almost nothing once they are flat. It is not a compression technique though: the output is still a three-channel JPEG, just with identical values in each. If you need a specific file size, use Compress JPG in target-size mode.
Can I get the colour back afterwards?
No. Colour information is discarded, not hidden — there is nothing left to restore. Keep your original and treat the black and white version as an export.
What does the contrast control do?
It pushes tones away from mid-grey (positive) or towards it (negative), applied after the conversion. A small positive amount — 10–20% — is often what makes a flat greyscale conversion look like a deliberate black and white photograph rather than a drained colour one.