QR code changed after I edited the image

Editing the image never edits the payload: the destination is fixed in the modules. What editing does do is damage them: rotation and resizing resample every module edge into a gradient, recolouring can destroy contrast or invert polarity. Decode the edited file to see what it says now, then re-export from the source.

Two separate misunderstandings, one page

"I edited the image and now the QR code is different" contains two failure modes, and it matters which one you have:

You edited pixels hoping to change the destination. That cannot work. The payload is encoded in the module pattern itself, the image is the data. No amount of retouching redirects a code; changing what it points to means changing the payload and generating a new code (and since static codes cannot be re-pointed after printing, read how to change what a QR code points to before assuming you can).

You edited the image cosmetically and it stopped scanning, or scans "wrong". This is the common case, and it is real damage. A decoder does not see your design. It sees a grid of dark and light squares and thresholds each one. Most image edits blur, shift or re-tint exactly those squares.

What each edit actually does

Edit	Damage mechanism
Rotate by anything but 90°/180°/270°	Resampling turns every crisp module edge into a gradient, a 1° "straighten" is enough
Scale down, then up again	Modules below ~4 px merge irreversibly; upscaling interpolates blur, it cannot restore them
Recolour / apply filters	Can collapse the ≥ 40% luminance contrast, or flip dark and light entirely
Invert / dark-mode the artwork	Light-on-dark polarity fails on many scanners: see inverted codes
Add drop shadows, glows, overlays	Gradient noise across modules and into the quiet zone
Crop "the empty border"	That border is the quiet zone; under 4 modules the code may not be found at all: see quiet zone too small
Save as JPEG after editing	Ringing artefacts at every module edge: see compression damage

The recolouring row deserves the emphasis: a decoder thresholds on luminance, not hue. Brand-tinting the dark modules to a mid-tone colour can leave a code that looks perfectly legible to you and reads as uniform grey to a camera.

The rule: edit the source, never the export

A QR image is an export, like a rendered PDF. The editable thing is the generator state that produced it. UseQR makes that state a URL: every field and style option is a query parameter, so the link in your browser bar is the source file. Change the colour, the logo, the error-correction level or the payload there, and re-export a fresh SVG, crisp modules, correct quiet zone, no resampling history. Keep that generator URL with your artwork files; if you already lost it, the recovery page covers rebuilding from a print.

Legitimate layout work (placing the code in a poster, scaling it) belongs in vector form (SVG or PDF), where scaling is lossless and edges stay mathematically sharp.

Check what it says now

Two checks settle any edited code:

Decode the edited file with our scanner. If it still decodes, read the string. It will be byte-identical to the original payload, confirming that pixel edits never changed the destination.
Run it through the validator, which renders, decodes and measures contrast, catching the marginal case where the edit weakened the code without killing it on your particular screen.

A code that survives both at final size is safe to print. A code that fails either goes back to the source state, not back into the editor.

FAQ

Can I change where a QR code goes by editing the image?

No. The destination is encoded in the module pattern: the image is the data. Changing the destination means generating a new code from a new payload. Image editors can only damage a code, never redirect it.

Why did my QR code stop working after I resized it?

Resampling. Shrinking merged modules that upscaling cannot restore, and non-integer scaling blurred module edges into gradients. Go back to the original export (ideally SVG, which scales losslessly), rather than resizing a raster copy.

Can I safely rotate a QR code in a design?

At exactly 90°, 180° or 270°, yes, modules map cleanly and scanners read codes at any orientation. Any other angle resamples every edge; even a 1° straighten degrades the code. Rotate vector exports if the layout demands an angle.

How do I check if my edited QR code still works?

Decode the edited file and compare the string with the original payload, then validate it at final print size for contrast and decodability. If either check fails, re-export from the generator instead of repairing pixels.