Film proofing
Photograph a strip of 35 mm on a light table, invert it, and you have a contact sheet without a scanner. Dust and the table’s colour cast come along, which is why there is a dedicated film page.
Browser tool · 6 modes · 0 uploads
Invert Image
Drop a photo, get its negative. Six invert modes, original resolution, and not one byte leaves the tab.
Drop an image, paste it, or click to choose
JPG · PNG · WebP · GIF · BMP — decoded on this device, never uploaded
Mode
Intensity
Output
Nothing is uploaded
The bytes stay in the tab. Clear the network panel, then invert a photo: no request appears, because the work happens in page memory.
Full resolution
No 2 MP preview cap, no server-side resize. A 48 MP frame comes back at 48 MP.
Six modes, not one
Whole image, a single channel, skin-safe, or dialled back to any strength between 0 and 100%.
About
What this conversion actually does
Inverting an image is subtraction: every colour channel is replaced by 255 minus its value. Black becomes white, white becomes black, and every hue lands on its complement. Phone cameras ship the same operation under the name "negative"; image editors call it "invert colors". This page does it at full resolution, in the browser, with no upload step and no account.
Most invert tools give you one button, which is fine for a glance and useless for the rest: keeping a face from turning blue, inverting a single channel for a two-plate print, or dialling the effect down to 40%. Those cases are the reason this tool has six modes instead of one.
Specification
What it accepts, and what it returns
| Input formats | JPG, PNG, WebP, GIF (first frame), BMP, AVIF where the browser decodes it |
|---|---|
| Maximum size | No fixed cap. Tested to 8000 × 6000 (48 MP) on a machine with 8 GB of RAM |
| Speed | 1920 × 1080 in well under a second; 48 MP in about four seconds |
| Transparency | Alpha is never touched. PNG output keeps it, JPG output is flattened onto white |
| Output | PNG (lossless, alpha preserved) or JPG at quality 0.92 |
| Uploads | None. The file is read with the File API and drawn to a canvas that never leaves the page |
Modes
Six modes, and when each one is the right call
| Mode | What it does | When to use it |
|---|---|---|
| Full invert | 255 − value on R, G and B | A true negative. Also the base layer for duotone and print work. |
| Red channel only | R inverted, G and B untouched | Pushes the whole image toward cyan-green. One plate of a two-colour screen print. |
| Green channel only | G inverted, R and B untouched | Magenta shift. Good for testing how a muted palette reads in print. |
| Blue channel only | B inverted, R and G untouched | Yellow shift. Useful for warm/cool split toning without a curve tool. |
| Smart invert (keeps skin) | Skips pixels inside the skin-tone range | Portraits. Faces stay recognisable while the background turns into a negative. |
| Intensity 0–100% | Blends the negative with the original | Anything that needs a hint of the effect rather than a full inversion. |
Method
Three steps
Drop the file
Drag it onto the panel, press Ctrl+V to paste from the clipboard, or click to pick from disk. The file is decoded locally with the File API — there is no upload endpoint in the code to call even if it wanted to.
Pick a mode
Full invert for a straight negative. Smart invert when there are faces in the frame. A single channel when you are building a duotone or a print separation. The slider blends any mode back toward the original.
Download
PNG keeps the alpha channel and is lossless, so inverting it again returns the exact original. JPG is smaller but re-encodes the pixels; choose it only for delivery, never for an intermediate step.
Use cases
What people actually use it for
Palette exploration
The negative of a good photograph is a ready-made complementary palette. Invert, screenshot the result, and sample four or five colours from it the next time a layout feels flat.
Dark-mode assets
Diagrams, charts and icons drawn for white backgrounds often survive inversion better than a hand-made dark variant. Check the result, then rebuild the two or three elements that break.
Contrast audits
A headline that disappears in the negative is a headline that is too light. Inverting is a crude but fast way to spot text that only works because of the background it sits on.
Screen printing and laser work
Etching and engraving are negative processes: what you burn away is what shows. Inverting artwork before sending it to the cutter is faster than rebuilding it in the vector editor.
Art and texture
Negatives of paper, concrete and foliage make convincing displacement and roughness maps. Invert once, desaturate, and the tonal range is already where a map wants it.
Under the hood
The arithmetic, in one paragraph
For 8-bit RGB the operation is out = 255 − in, applied to each channel independently. Doing it twice returns the original exactly, because 255 − (255 − x) = x. There is no rounding, no colour-space conversion and no accumulated error — which is why a PNG round trip through this tool is bit-identical, while a JPEG round trip is not.
Because channels are independent, inverting one of them is a hue rotation of exactly 180° around that axis rather than a global inversion. That is what the single-channel modes are for: they move the image toward cyan, magenta or yellow without destroying the tonal structure.
Questions
Answered plainly
Is it really free, with no account?
Yes. No sign-up, no watermark, no daily quota and no file-count limit. The tool runs entirely in the page, so there is no server cost to pass on to you.
Do you upload my images?
No. The file is read with the File API and processed on a canvas. You can confirm it yourself: open the browser network panel, clear it, then invert a photo. No new request appears.
Can I invert several images at once?
Select multiple files, or drop a whole folder’s worth onto the panel. Each file is queued, processed one at a time, and you can download them individually or as a single ZIP.
What happens to transparent areas?
Only RGB is inverted; the alpha channel is copied through untouched. A transparent PNG stays transparent, and semi-transparent edges keep their exact opacity.
Does it work on a phone?
Yes. The layout is built for a single column, and iOS and Android both allow picking a photo from the camera roll or the camera. Large files may take a second longer on older hardware.
Should I download PNG or JPG?
PNG if the image has transparency, if you plan to invert it again, or if it is going to a printer. JPG only when file size matters more than fidelity — it re-encodes and loses a little every save.
What comes next
A server-side API and a desktop batch runner are planned. The browser tool above stays free and unlimited: no account, no watermark, no file cap.
Free, permanently
Full resolution, all six modes, batch and ZIP. If a page ever asks you to register to invert an image, it is not this one.
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