This Bookmarklet Overlays Rule of Thirds Gridlines to Photos in Your Browser


Want to see whether or not your favorite photographers are following the rule of thirds when composing their shots? Programmer and photography enthusiast Alex Dergachev has created a simple browser bookmarklet that overlays RoT gridlines over any (or almost any) web photograph.

To get started, visit the bookmarklet’s website and drag the button to your browsers bookmark bar:


That’s it. Now, anytime you want to see what the gridlines look like on a photo that catches you eye, simply click that bookmark. All the photographs on the page will instantly turn monochrome, and the black-and-white dashed gridlines will appear over them.

The screenshot above shows what resulted when we tested the bookmarklet on the current frontpage of Time’s Lightbox, which features a photo of President Obama shot by chief White House photographer Pete Souza.

The code used for the tool is open source over on GitHub, so you can fork the project and tweak it to suit your own needs (e.g. remove the desaturation step, change how the gridlines look).

Rule-of-thirds Bookmarklet [Blocks]

  • BTarr

    Yes, because it’s so hard for me to see this without obnoxious lines in the photo…

  • Stephen Holmes


  • Mantis

    Lighten up, Francis.
    It’s just a learning tool.

  • cheap shots for real

    you could get the same results by drawing actual lines on your monitor with permanent marker… why not try that? no scripts, no bookmarks, just analogue common sense! 8-l

  • BTarr

    You’re right, we should definitely imply that the rule of thirds is a “rule” at all, too. That’s key for new photographers who are learning……. let’s get them started right away with arbitrary rules.

  • OSAM

    Because we always view images in websites as full-screen images and not as anything smaller…

  • Jackson Cheese

    Some of you people take this hobby way to f’ing seriously.

  • lidocaineus

    Comments like this are incredibly ignorant. Rules, in terms of art and even things like science, are there for a very important purposes: when you’re starting out, they provide an excellent STARTING POINT that will enhance your likelihood of creating something you and others will find pleasing. Does it guarantee it? Of course not, but it increases your chances, especially when you combine these rules together. After you start learning what makes a photo work and begin figuring out your own creative vision, you can then start bending and breaking rules to fit what you want, all the while understanding why something does or does not work, and why you would break a rule or keep it in place.

    This is called theory, and is a foundation for almost anything out there. Do you know how painful it is or difficult it is for someone to start out with something new and not have any guidelines? To be just thrown out there and told to “go nuts, do what you want!” They’ll wonder why their photos don’t work, why they can’t even expose properly, why they feel like everything is luck of the draw, and you’ll end up with bad habits like spraying-and-praying. Worst of all, the person won’t be able to articulate WHY they do or do not like a photo.

    Rules can and should be broken. But you should know why and when.

  • Joey Duncan

    Well put.

  • Mantis

    Perfectly stated.

  • Leonardo Abreu

    Very cool :)

  • Joe

    For some people it’s more than a hobby.

  • BTarr

    Composing everything in thirds is a habit I wish I never picked up while I was learning. You’re entitled to your opinion on this… Let’s leave it at that. And you don’t need the ad homs, really, when you’re trying to take the higher ground.

  • lidocaineus

    That really makes no sense – you didn’t want to learn about the rule of thirds? If you have reasons for not abiding by it, you clearly learned something about why it does or does not work for you.
    This is already miles ahead of someone who didn’t know about thirds and can’t explain why certain photos appeal or do not appeal to them based on positioning. Learning technique isn’t just about finding things that work for you – part of it is understanding things that DON’T work and why; this helps you avoid it in your own work and structure opinions on why you don’t like things in others’ work.

    There are no ad hominems in my statement – I called your comment’s subject ignorant, not you. What you’re advocating for is active ignorance. You may not like having being forced to compose in thirds in the past but you gained plenty from it, like the fact that you don’t like the results. The alternate is not doing it and not knowing if it would help or hinder your results. That’s pretty much the definition of ignorance.

  • Dan Howard


  • Neoracer Xox

    I”ve taken screen shots from some classic movies and directors (like Ridley Scott) and more often than not the compositions are bang on with the rule of 3rds and the Golden Ratio, its quite startling. I wonder if they do it consciously or sub consciously as artisans in their field. But it WORKS.

  • Voodoo

    Rule of thirds and other such methods are technical things, this should become internal overtime when one shoots…much like dribbling a basketball or playing with a yoyo (before you learn trick on a yoyo, you have to know how to control the string and the spinner) if you’ve been taking pictures for awhile now and still trying to learn the rule, then i’ve got news for you…

  • treisise

    A rule should be broken at every opportunity – this one in particular – people force things to fit this ‘rule’ and make any picture fit it is so ‘flexible’ it can be made to fit any image you wish to.