Here you’ll find a list of tools, libraries, polyfills and other kinds of open source scripts I’ve developed over the years. Some of them only work in recent browsers. Also, obviously if you use a tool to help you with an experimental CSS feature, it probably won’t work in browsers that don’t support that feature.

Contrast Ratio

Contrast Ratio is a modern tool for testing whether a combination of colors passes WCAG 2.0. It accepts any CSS color the browser accepts, including semi-transparent colors, color keywords, HSL(A) colors and the like. You can also share color combinations with others by just sharing the current URL.


Prism is a new lightweight, extensible syntax highlighter, built with modern web standards in mind. It’s a spin-off from Dabblet and is tested there daily by thousands.


An interactive CSS playground. Pretty much my most successful project so far, with thousands of visitors every day.


A CSS transitions gallery that shows what’s possible with even the most basic of transitions: one property, two values.


-prefix-free is a library that allows you to write standard, prefix-less CSS and have the necessary prefixes added on runtime. It uses feature detection for almost everything.

A tool that helps you work with the easing functions of CSS3 transitions & animations and share them with others.


A tool that helps you convert between the different CSS-accepted color formats (including name keywords) as well as share them with others.

CSS3 patterns gallery

An interactive gallery that demonstrates what’s possible with just CSS gradients. It also allows you to edit the code, to experiment with gradients yourself.


Chainvas is a tiny generic chaining library that can make any API’s methods chainable (like jQuery). Official plugins for the DOM and the Canvas API included.


A script that enables incrementing/decrementing multiple numeric values in textfields with the keyboard arrow keys.


My popular slideshow framework, built exclusively with open web technologies. Includes plugins for editable CSS regions, syntax hightlighting and more.


A server-side script that automatically generates semi-transparent PNGs to be used as fallbacks for RGBA colors.

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  • rex_mizan

    Great works!!

  • Phil

    Love your Work! Thank you!

  • Keonne Rodriguez

    You’re pretty amazing Lea. This is an awesome body of work.

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  • Eduard Gotwig

    Hey, might you please take a look at ? its an web based editor for presentations, realized with impress.js as library.

  • Rayman Design

    Congratulations Lea V is cool this work

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  • sd


    • df


  • Tom

    How old are you? You don’t waste time right?

    • Lea Verou

      26. Oh I waste plenty of time :) Wasting time is the best way to get new ideas ;)

      • Aklavya

        It just awesome ! ..and looking coolest all of your project…… Lea .. I Salute your work…. i really get newest idea by giving time to your website..Thanks.


        now i am thinking to waste time more more times get new ideas….

      • Weslie Khan

        I thought I was the only one doing that…best of luck

      • Danu

        woman can never pass the age 26 :P

      • Eddy

        Seeing that you are only 26 and have accomplished so much has inspired me to accomplish even more by the age of 25. Thank you for this.

      • Govind Yaswanth

        She had started her technical life from the stage, when we are still fighting with graduation.

        She started her technical life in her diploma itself

      • Bilal Khoukhi

        Are you still 26?

        • Lea Verou

          As you can see, that comment was posted over a year ago. I don’t have time-stopping superpowers :P

        • Bilal Khoukhi

          I also saw a comment by someone say that women can never pass 26 :P , Plus I saw your pics, you don’t look 27 at all

  • Per Rosendahl

    Awesome work!

  • HaroonAbbasi

    Amazing list of work.

  • dhiran

    Great jobs!

  • shivam chopra

    You are pretty cool…!!! you’ve done amazing work.

  • Arnold Roa

    You are amazing!

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  • 心吾


  • Srirang Gawli

    Excellent Work Lea…

  • Gujaalboy

    I love you!

  • <OMG

    Amazing works Lea , youre amazing girl too.

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  • Jayme Cousins

    I bow before the brilliance!

  • Jorge Luis Dueñas

    Congratulations :) you’re so amazing

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  • Barun Bhaumik

    I want to create blog section.Can you help me.please mail me.

  • Barun Bhaumik

    You and your thinking is cool. Are you 26. But your new ideas are too excellent for me.I am a web designer and I used your tutorial for my design.Many many thanks to you.

  • Barun Bhaumik

    I am wordless to appreciate you!!! You dont know what you have created for us, the wed designers cum developers. I personally appreciate you “carry on”.

  • rewrwr


  • Hemant S Kukreja

    What inspires you to do all this!! Everyone has a stoppage but it doesnt seems in your case!

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  • Joby Tom

    Great Works!

  • razaqnice


  • DanOwen

    Love your CSS3 Secrets slideshow. It’d be nice if you indicated Chrome compatibility.

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  • MockingBird

    I love your works so much, Lea!!

  • tormahirtormahiri

    مەن سەل ھەيران قالدىم
    i wondering little bit

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  • Mampel

    Nice work Lea Verou!

  • Kshitiz Rimal

    your profile is inspiring, i knew about your projects but i didn’t know it was build by you. amazing collection

  • David Hc

    Dude, i love prefix-free.js :) a nice work. I free from hell now :p

  • carlos

    This it my new best place, Regards lea excelents work.
    Hug from the south of world

  • Bruno Gomes

    rgba.php Makes my life so much better. Thank you for that! <3

  • Patrick Matthews

    your site certainly taught me something new today!

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  • victor alfonso caballero cabre


  • Marcelo Silva

    Amazing projects!!! Hugs.

  • tomjamescn

    So Greate Job!

  • Eriky Pessoas

    I’m your fan….
    Great works

  • Massimo Ivaldi

    I am admired: you are a great artist

  • Kareem Ahmed

    i think this list needs “colorzilla” added to it they have the best CSS Gradient Generator i have ever seen on web

    • Lea Verou

      As I thought was obvious, this list is projects I’ve made. I didn’t make ColorZilla, so no it’s not missing from the list. You just misunderstood what the list is about.

      • Kareem Ahmed

        i’m very sorry for that mistake .. i must have been excited to see lots of lovely tools in one place that i thought of adding another, and forgot to read the paragraph above :) .. again sorry

  • Alexander Wasilich

    Thank for the “prefixfree.js”!!!
    But what about “filter: greyscale (%);”

  • TechnoKnol

    Awesome… It looks like you have Ph.D. degree in web developing :)

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  • Architektura Architekt

    chapeau bas

  • william otto

    you’re so cool, finding this now makes me sad about leaving the world of web design,,,

  • Chris Lowles

    Thank f**k I found -prefix-free

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  • Tho Vo

    Hi Lea,
    The link for corner shape is incorrect, could you please fix it?

    Thank you a lot for your hard working :)

    • Lea Verou

      Fixed, thanks!

  • Andelina

    It is so cool,I like it!

  • Andelina

    This is my first time have saw so cool web,I really like it! I’m from China

  • Pedro Carvalho

    Your work is admirable both as in quality and quantity. Congratulations!

    • Lea Verou


  • JCinDE

    Saw your Play by Play on Pluralsight. Good stuff!

  • beagledog1

    Pretty good stuff.

  • Milad

    you are the best !!!!! im depressed now after seen your web site and portfolio !!!!