How to use it
- Choose a photo with the file picker. It is read in your browser and is not uploaded.
- Tick the guides you want: Thirds, Golden ratio or Diagonals.
- Pick a Colour and a Line width that show well on your photo.
- Read the positions under the picture, in pixels, to place the main subject on a line or a crossing.
- Press Download to save the photo with the guides as a PNG file.
What the rule of thirds sets out
The frame is divided into nine equal parts by two horizontal and two vertical lines. Adobe's guide calls the four points where the lines cross power points, and the usual use is to place the subject at one of them or along one of the lines.
thirds across = width ÷ 3 and width × 2 ÷ 3
thirds down = height ÷ 3 and height × 2 ÷ 3The golden ratio and the diagonals
The golden ratio φ = (1 + √5) ÷ 2 = 1.6180339887 is the proportion in which a whole divides into a larger part a and a smaller part b: (a + b) ÷ a = a ÷ b = φ. The golden guides sit at 1 ÷ φ² = 0.382 and 1 ÷ φ = 0.618 of each side, so they lie close to, but not on, the thirds at 0.333 and 0.667.
The diagonals run from each corner to the opposite corner, so the two of them cross in the middle of the picture.
φ = (1 + √5) ÷ 2 = 1.6180339887…
golden guides = width ÷ φ² and width ÷ φ (0.382 and 0.618 of the width), the same for the heightWhat the page does not do
- It does not judge the picture: the rule is a guide for composing, not a requirement.
- It does not change the photo: the lines are drawn on a copy, and the download is the photo's own size with the guides on it.
- It does not upload the photo: the file is read in your browser and is never sent anywhere.
Worked example: a 3,000 × 2,000 pixel photo
With the thirds and the golden guides on, the readout for a 3,000 × 2,000 pixel photo gives the thirds at 1,000 and 2,000 pixels across and at 667 and 1,333 pixels down. The golden guides fall at 1,146 and 1,854 pixels across and at 764 and 1,236 pixels down. Two thirds of 2,000 is 1,333.3, shown as 1,333, and 0.618 of 3,000 is 1,854.1, shown as 1,854.
| Guide | Across (pixels) | Down (pixels) |
|---|---|---|
| Thirds | 1,000 and 2,000 | 667 and 1,333 |
| Golden ratio | 1,146 and 1,854 | 764 and 1,236 |
Frequently asked questions
What is the rule of thirds?
The rule of thirds divides a photo into nine equal parts with two horizontal and two vertical lines. It is a composition guide, and the usual use is to place the main subject on one of the lines or at a crossing point.
Is the golden ratio the same as the rule of thirds?
No. The golden guides lie at 0.382 and 0.618 of each side, while the thirds lie at 0.333 and 0.667, so the two sets of lines are close but not the same. Use the set that suits the picture.
Why does the page include the diagonals?
The diagonals run from corner to corner and form a third kind of guide. The page draws them with the other two, and you can switch each set on or off.
Does the page keep my photo?
No. The photo is read in your browser, and the page does not upload it or store it. The download is saved to your device only when you press the button.
Why is the download the photo's own size?
The download keeps the photo's own size, up to 16 megapixels, so the guides fall exactly where they fall on the photo. The preview is smaller only so that the page stays quick on a phone.
Can I change the colour and the thickness of the lines?
Yes. The colour and the line width apply to all the guides. The width is scaled to the photo, so the lines keep the same proportion on a large photo and on a small one.
Sources
- Adobe: Rule of thirds, nine equal parts and the four power points
- MathWorld: Golden Ratio, the defining proportion, the closed form and the value
Figures and text last checked on Thursday, November 12, 2026.