Rightmove watermark rules: white, 30% opacity, quarter size

On Rightmove only white, translucent watermarks are allowed, they may be no larger than one quarter of the overall image, and their opacity should be 30% or lower. A watermark is only for preventing image copyright and should carry no further messaging, so no phone numbers or taglines. Anything else is the quickest way to get a listing image rejected, so build the watermark into your export step, not your generation prompt.

The rules are in Rightmove's technical guidelines (January 2026), read on 2026-10-02.

What are the image numbers?

Rightmove's help page gives sizes and ratio along with the guideline watermark rule.

Should a generated image carry the watermark?

A watermark identifies the photographer, so put it on your real photos. Do not ask an image model to draw a watermark: it will not respect 30% opacity or a quarter size reliably, and Sume's Image API does not take explicit pixel sizes. Apply it afterwards with a script.

A script that applies a compliant mark

This Pillow script pastes a white logo at 25% of the image width (a narrower logo than the quarter-area cap) with 30% opacity.

from PIL import Image

img = Image.open("photo.jpg").convert("RGBA")
mark = Image.open("logo-white.png").convert("RGBA")
w = img.width // 4
mark = mark.resize((w, int(mark.height * w / mark.width)))
alpha = mark.getchannel("A").point(lambda a: int(a * 0.3))
mark.putalpha(alpha)
x = img.width - mark.width - 24
y = img.height - mark.height - 24
img.alpha_composite(mark, (x, y))
img.convert("RGB").save("photo-marked.jpg", quality=92)
print("saved", img.size)