Red Eye Removal That Keeps the Catchlight
The flash only affected the red channel, so green and blue still hold the real brightness of the eye. Bringing red down to meet them fixes the colour and leaves the catchlight exactly where it was, instead of painting the pupil black.
Drop images here
or click to browse · or paste with Ctrl+V
JPG · PNG · WebP · GIF · BMP · AVIF
Drag a box over each eye on the preview. Only pixels inside it that are genuinely red get corrected, so a rough box is fine and there is no need to trace the pupil.
Lower catches more of the pupil. Raise it if skin or lips inside your box are being corrected too.
A corrected pupil is often a little pale. A small amount here restores the depth without touching the catchlight.
Presets
Your photos are never uploaded. The correction runs inside this browser tab, which matters for family photos.
People also use
Everything this tool does
The catchlight survives
Red is brought down to meet green and blue rather than being replaced. On a test eye, the pupil went from 210,42,38 to 40,42,38, a redness of 0.81 down to 0.00, while the catchlight came through at 255 in all three channels.
A rough box is enough
The box limits where to look; the redness test does the selecting. On a test eye surrounded by skin, every pupil pixel was corrected and not one of the 2,208 skin pixels inside the box changed.
Nothing outside your boxes
Pixels outside the marked regions are copied through unchanged, verified across the whole image.
A soft threshold
The correction fades in above the threshold rather than switching on, so there is no hard rim between corrected and untouched pixels around the pupil.
Optional pupil deepening
A corrected pupil can look a little pale, since the flash lifted its brightness too. A small deepening restores the depth without flattening the catchlight.
Any number of eyes
Drag once per eye, as many as the photo needs, with a clear all button. Regions are stored as percentages so they land correctly at full resolution.
Drag to compare
Before and after share one frame with a slider between them.
Six purpose-built presets
Standard, strong red eye, faint or partial, careful, no deepening and deep pupil.
Batch with one ZIP
Useful for a burst of frames taken from the same position, where the eyes are in roughly the same place.
Nothing is uploaded
No server, no queue, nothing to delete afterwards, which matters when the photo is of your family.
What each control does
A rough box is all the tool needs, because the redness test does the actual selecting. The threshold decides how red a pixel must be, and it is the only control most photos need.
| Setting | What it does | Try | Watch for |
|---|---|---|---|
| Threshold 20-30 | catches faint red eye | strength 100 | Skin corrected too |
| Threshold 40-60 | only strong red | strength 100 | Pale rim left behind |
| Strength 100 | full correction | most photos | Nothing much |
| Strength 60-80 | partial, for faint cases | any threshold | Residual pink |
| Deepen 0 | keeps the original brightness | bright eyes | Pupil looks pale |
| Deepen 20-40 | restores pupil depth | most photos | Catchlight dulled |
| Box size | roughly around the eye | generous | Nothing, it is filtered |
Drag
a box per eye
0
files uploaded
0
pixels changed outside your boxes
Kept
catchlight
ZIP
batch download
Free
no account needed
FlipMyFormat vs other red eye tools
| Capability | FlipMyFormat | Typical free tool |
|---|---|---|
| Files stay in your browser | ||
| The catchlight is preserved | ||
| Only genuinely red pixels are corrected | ||
| A rough box is enough, no tracing | ||
| Nothing outside your boxes is touched | ||
| Batch ZIP download without paying | ||
| No watermark on the output |
How to fix red eye without killing the eye
Red eye happens when a flash sits close to the lens: the light goes into the eye, reflects off the blood-rich retina and comes straight back, so the pupil records as bright red instead of black. The important thing about that description is that it is a red-channel problem. The green and blue channels were barely affected, which means they still contain an accurate record of how bright each part of the eye was, including the small white catchlight where the flash reflected off the wet surface. That catchlight is what makes an eye look alive, and the most common failure in red eye correction is painting the pupil a flat black and destroying it. The eye ends up looking like a hole. The correction here brings the red channel down to match green and blue rather than replacing anything, so wherever the eye was bright it stays bright and wherever it was dark it stays dark. The other decision worth understanding is what gets corrected. Rather than treating your box as the selection, the tool measures how far each pixel's red exceeds its green and blue, and only acts where that excess is large. Skin is warm but nowhere near as red as a flash reflection, so it fails the test and is left alone. That is why a rough box is enough and why you never need to trace around a pupil. If skin inside your box is being corrected, the threshold is simply too low.
- 1
Add the photo
Drag it in, click to browse, or paste with Ctrl+V. It stays on your device, which matters for family photos.
- 2
Drag a box over each eye
Rough is fine. Only pixels inside the box that are genuinely red get corrected, so there is no need to trace the pupil.
- 3
Adjust and export
If skin inside the box is being corrected, raise the threshold. A little pupil deepening usually finishes it off.
Why green and blue are the key
Only the red channel was damaged
The retinal reflection is red, so it added enormously to the red channel and very little to green and blue. Those two channels are therefore an intact record of the eye's actual brightness, and the correction is simply to bring red down to meet them. The consequence is the thing that matters: the catchlight, which is a small bright spot where the flash reflected off the surface of the eye, was bright in all three channels, so pulling red down leaves it bright. We test it directly on a synthetic eye containing a red pupil and a white catchlight: after correction the pupil's redness dropped from 0.81 to 0.00, the pixel going from 210,42,38 to 40,42,38, while the catchlight came through at 255 in all three channels, exactly as it started. A tool that paints the pupil black takes that catchlight with it.
Redness, not redness inside a box
The box you drag is a limit on where to look, not the selection itself. Within it, each pixel is measured for how far its red channel exceeds the average of its green and blue, relative to its own brightness. A flash reflection scores very high on that measure; skin, which is warm but nothing like as red, scores far lower; and lips sit between the two but still well below a pupil. Only pixels above the threshold are touched, and the correction fades in above it rather than switching on, so there is no hard rim between corrected and untouched pixels. We check the practical consequence on a test eye surrounded by skin: with a box covering both, every pupil pixel was corrected and not one of the 2,208 skin pixels inside the box changed. The measure also ranks correctly, scoring 0.81 for the pupil, 0.51 for lips and 0.31 for skin. Everything outside your boxes is copied through untouched, which we verify across the whole image.
What people use it for
Family and party photos
The classic case. Compact cameras and phone flashes sit close to the lens, which is exactly what causes red eye.
Old scanned photographs
Film compacts had the worst flash placement of all, so scanned family albums are full of it.
Group shots
Several eyes need fixing in one frame, and each takes one drag.
Passport and ID photos
Red eye is a common rejection reason, and a correction that keeps the catchlight looks natural.
Event photography
Indoor events shot with on-camera flash produce it constantly.
Pet photos
Animals show green or yellow eye shine rather than red, which this cannot fix, though a low threshold sometimes helps.
Printing family albums
Red eye is far more obvious in print than on a phone screen, so it is worth fixing before printing.
Social media
A quick fix before posting, with the photo never leaving your device.
Six tips worth knowing
Draw the box generously. It only limits where the tool looks, and the redness test does the actual selecting.
If skin or lips inside your box are being corrected, raise the threshold. That is the only control most photos need.
Add a little pupil deepening. The flash brightened the whole eye, so a corrected pupil often looks slightly pale without it.
Do not paint the pupil black in another tool. The catchlight is what makes an eye look alive, and losing it is worse than the red.
Check the exported file rather than the preview, since an eye is small and the preview runs on a smaller copy.
Animals show green or yellow eye shine, not red, so this often will not help with pets.
Troubleshooting
Skin inside the box changed colour
The threshold is too low. Skin is warm but far less red than a flash reflection, so raising it will exclude the skin and keep the pupil.
There is a pink rim left around the pupil
Those pixels are less red than the centre and fall below the threshold. Lower it slightly until the rim is included.
The pupil looks pale and flat
Add some pupil deepening. The flash lifted the brightness of the whole eye, so simply removing the red can leave it lighter than it should be.
It did not work on my pet
Animal eye shine is usually green or yellow, caused by a reflective layer behind the retina that humans do not have. This tool targets red specifically.
Frequently asked questions
What causes red eye?
A flash close to the lens. Light enters the eye, reflects off the blood-rich retina and comes straight back into the lens, so the pupil records as bright red instead of black.
Why does the catchlight matter?
It is the small bright spot where the flash reflected off the wet surface of the eye, and it is what makes an eye look alive. Painting the pupil black removes it and the eye ends up looking like a hole.
How is it preserved here?
The flash reflection only added to the red channel, so green and blue still hold the eye's real brightness. Bringing red down to meet them leaves anything that was bright still bright, including the catchlight.
Can you show that?
On a synthetic eye with a red pupil and a white catchlight, the pupil went from 210,42,38 to 40,42,38 after correction, a redness of 0.81 down to 0.00, while the catchlight came through at 255 in all three channels.
Do I need to trace around the pupil?
No. The box only limits where the tool looks, and each pixel is then measured for how far its red exceeds its green and blue. A rough box is enough.
Will it change skin inside my box?
It should not. Skin is warm but nowhere near as red as a flash reflection: the measure scores 0.81 for a pupil, 0.51 for lips and 0.31 for skin. On a test eye surrounded by skin, not one of the 2,208 skin pixels inside the box changed.
Skin did change. What now?
Raise the threshold. That is the only control most photos need, and it excludes anything less red than a genuine reflection.
There is a pink rim left around the pupil
Those pixels are less red than the centre and are falling below the threshold. Lower it slightly until the rim is included.
Why is my corrected pupil pale?
The flash brightened the whole eye, not just its colour, so removing the red can leave it lighter than it should be. Add some pupil deepening.
Does it work on animals?
Usually not. Animal eye shine is green or yellow, caused by a reflective layer behind the retina that humans do not have, and this targets red specifically.
Can I fix several eyes at once?
Yes. Drag once per eye, as many as the photo needs, and clear them all with one button if you want to start again.
Will the box land correctly at full resolution?
Yes. Regions are stored as percentages of the image rather than pixels, so what you marked on the preview lands in the same place on the full size file.
Does anything outside my boxes change?
No. Those pixels are copied through unchanged, verified across the whole image.
Are my photos uploaded to a server?
No, and it matters here more than on most tools. Everything runs in your browser, so a family photo is not sent to us or anyone else.
Which format should I export?
Keep the original for photographs, at quality 90 or above. An eye is small and high contrast, which is where JPEG artefacts show most.
Is transparency preserved?
Yes for PNG and WebP output. The alpha channel is untouched. JPG has no alpha, so transparent areas are filled with the background colour first.
Can I process a batch?
Yes, though it only makes sense for a burst of frames taken from the same position where the eyes fall in roughly the same place.
Does it add a watermark or need an account?
No to both. No sign-up, no email wall, no daily limit and no watermark on the output.