Physical Pixels vs CSS Pixels vs Device Independent Pixels vs Density Independent Pixels vs PPI












9














I am learning web development and I am having a hard time determining what is equivalent in all of this.



I know hardware pixels and physical pixels are the smallest unit, and that density independent pixels map to actual hardware pixels via a device pixel ratio and they are used to make the viewing experience more consistent. Does this mean that the device independent pixels I'm seeing are the same thing?



Further, I read that the browser reports viewport width in CSS pixels, are these and DIPs the same thing?



I know that Pixels per inch are literal, they are the number of pixels in an inch, but how do they relate to DIPs? A totally separate measurement? When should I use that instead?



I hope this is an appropriate question, I am having issues mentally linking all of these concepts into one usable map, and didn't find any other question where they are all addressed at once.










share|improve this question



























    9














    I am learning web development and I am having a hard time determining what is equivalent in all of this.



    I know hardware pixels and physical pixels are the smallest unit, and that density independent pixels map to actual hardware pixels via a device pixel ratio and they are used to make the viewing experience more consistent. Does this mean that the device independent pixels I'm seeing are the same thing?



    Further, I read that the browser reports viewport width in CSS pixels, are these and DIPs the same thing?



    I know that Pixels per inch are literal, they are the number of pixels in an inch, but how do they relate to DIPs? A totally separate measurement? When should I use that instead?



    I hope this is an appropriate question, I am having issues mentally linking all of these concepts into one usable map, and didn't find any other question where they are all addressed at once.










    share|improve this question

























      9












      9








      9


      7





      I am learning web development and I am having a hard time determining what is equivalent in all of this.



      I know hardware pixels and physical pixels are the smallest unit, and that density independent pixels map to actual hardware pixels via a device pixel ratio and they are used to make the viewing experience more consistent. Does this mean that the device independent pixels I'm seeing are the same thing?



      Further, I read that the browser reports viewport width in CSS pixels, are these and DIPs the same thing?



      I know that Pixels per inch are literal, they are the number of pixels in an inch, but how do they relate to DIPs? A totally separate measurement? When should I use that instead?



      I hope this is an appropriate question, I am having issues mentally linking all of these concepts into one usable map, and didn't find any other question where they are all addressed at once.










      share|improve this question













      I am learning web development and I am having a hard time determining what is equivalent in all of this.



      I know hardware pixels and physical pixels are the smallest unit, and that density independent pixels map to actual hardware pixels via a device pixel ratio and they are used to make the viewing experience more consistent. Does this mean that the device independent pixels I'm seeing are the same thing?



      Further, I read that the browser reports viewport width in CSS pixels, are these and DIPs the same thing?



      I know that Pixels per inch are literal, they are the number of pixels in an inch, but how do they relate to DIPs? A totally separate measurement? When should I use that instead?



      I hope this is an appropriate question, I am having issues mentally linking all of these concepts into one usable map, and didn't find any other question where they are all addressed at once.







      html css






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked Jan 25 '17 at 23:24









      Leah Denham

      5116




      5116
























          1 Answer
          1






          active

          oldest

          votes


















          10















          I know hardware pixels and physical pixels are the smallest unit, and that density independent pixels map to actual hardware pixels via a device pixel ratio and they are used to make the viewing experience more consistent. Does this mean that the device independent pixels I'm seeing are the same thing?



          Further, I read that the browser reports viewport width in CSS pixels, are these and DIPs the same thing?




          Yes on both counts. For example, an element with height: 200px; width: 200px is always 200 by 200 in DIPs or CSS pixels, even if the hardware is configured to display at a higher or lower resolution than usual. At a scale factor of 200%, if a 1x1 DIP or CSS pixel maps to a 1x1 physical pixel in 100%, it will map to a 2x2 physical pixel square.




          I know that Pixels per inch are literal, they are the number of pixels in an inch, but how do they relate to DIPs? A totally separate measurement?




          CSS does not use PPI; it only uses DPI. Section 6.4 of css-values-3 lists the following units:




          dpi

          Dots per inch.



          dpcm

          Dots per centimeter.



          dppx

          Dots per px unit.



          The <resolution> unit represents the size of a single "dot" in a graphical representation by indicating how many of these dots fit in a CSS in, cm, or px.




          For the purposes of CSS and Media Queries, a single "dot" always corresponds to a single physical pixel, never a DIP or CSS pixel, hence the dppx unit. For example, a scale factor of 200% or device pixel ratio (non-standard) of 2.0 is equivalent to 2 dppx.






          share|improve this answer























            Your Answer






            StackExchange.ifUsing("editor", function () {
            StackExchange.using("externalEditor", function () {
            StackExchange.using("snippets", function () {
            StackExchange.snippets.init();
            });
            });
            }, "code-snippets");

            StackExchange.ready(function() {
            var channelOptions = {
            tags: "".split(" "),
            id: "1"
            };
            initTagRenderer("".split(" "), "".split(" "), channelOptions);

            StackExchange.using("externalEditor", function() {
            // Have to fire editor after snippets, if snippets enabled
            if (StackExchange.settings.snippets.snippetsEnabled) {
            StackExchange.using("snippets", function() {
            createEditor();
            });
            }
            else {
            createEditor();
            }
            });

            function createEditor() {
            StackExchange.prepareEditor({
            heartbeatType: 'answer',
            autoActivateHeartbeat: false,
            convertImagesToLinks: true,
            noModals: true,
            showLowRepImageUploadWarning: true,
            reputationToPostImages: 10,
            bindNavPrevention: true,
            postfix: "",
            imageUploader: {
            brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
            contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
            allowUrls: true
            },
            onDemand: true,
            discardSelector: ".discard-answer"
            ,immediatelyShowMarkdownHelp:true
            });


            }
            });














            draft saved

            draft discarded


















            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f41863545%2fphysical-pixels-vs-css-pixels-vs-device-independent-pixels-vs-density-independen%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown

























            1 Answer
            1






            active

            oldest

            votes








            1 Answer
            1






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes









            10















            I know hardware pixels and physical pixels are the smallest unit, and that density independent pixels map to actual hardware pixels via a device pixel ratio and they are used to make the viewing experience more consistent. Does this mean that the device independent pixels I'm seeing are the same thing?



            Further, I read that the browser reports viewport width in CSS pixels, are these and DIPs the same thing?




            Yes on both counts. For example, an element with height: 200px; width: 200px is always 200 by 200 in DIPs or CSS pixels, even if the hardware is configured to display at a higher or lower resolution than usual. At a scale factor of 200%, if a 1x1 DIP or CSS pixel maps to a 1x1 physical pixel in 100%, it will map to a 2x2 physical pixel square.




            I know that Pixels per inch are literal, they are the number of pixels in an inch, but how do they relate to DIPs? A totally separate measurement?




            CSS does not use PPI; it only uses DPI. Section 6.4 of css-values-3 lists the following units:




            dpi

            Dots per inch.



            dpcm

            Dots per centimeter.



            dppx

            Dots per px unit.



            The <resolution> unit represents the size of a single "dot" in a graphical representation by indicating how many of these dots fit in a CSS in, cm, or px.




            For the purposes of CSS and Media Queries, a single "dot" always corresponds to a single physical pixel, never a DIP or CSS pixel, hence the dppx unit. For example, a scale factor of 200% or device pixel ratio (non-standard) of 2.0 is equivalent to 2 dppx.






            share|improve this answer




























              10















              I know hardware pixels and physical pixels are the smallest unit, and that density independent pixels map to actual hardware pixels via a device pixel ratio and they are used to make the viewing experience more consistent. Does this mean that the device independent pixels I'm seeing are the same thing?



              Further, I read that the browser reports viewport width in CSS pixels, are these and DIPs the same thing?




              Yes on both counts. For example, an element with height: 200px; width: 200px is always 200 by 200 in DIPs or CSS pixels, even if the hardware is configured to display at a higher or lower resolution than usual. At a scale factor of 200%, if a 1x1 DIP or CSS pixel maps to a 1x1 physical pixel in 100%, it will map to a 2x2 physical pixel square.




              I know that Pixels per inch are literal, they are the number of pixels in an inch, but how do they relate to DIPs? A totally separate measurement?




              CSS does not use PPI; it only uses DPI. Section 6.4 of css-values-3 lists the following units:




              dpi

              Dots per inch.



              dpcm

              Dots per centimeter.



              dppx

              Dots per px unit.



              The <resolution> unit represents the size of a single "dot" in a graphical representation by indicating how many of these dots fit in a CSS in, cm, or px.




              For the purposes of CSS and Media Queries, a single "dot" always corresponds to a single physical pixel, never a DIP or CSS pixel, hence the dppx unit. For example, a scale factor of 200% or device pixel ratio (non-standard) of 2.0 is equivalent to 2 dppx.






              share|improve this answer


























                10












                10








                10







                I know hardware pixels and physical pixels are the smallest unit, and that density independent pixels map to actual hardware pixels via a device pixel ratio and they are used to make the viewing experience more consistent. Does this mean that the device independent pixels I'm seeing are the same thing?



                Further, I read that the browser reports viewport width in CSS pixels, are these and DIPs the same thing?




                Yes on both counts. For example, an element with height: 200px; width: 200px is always 200 by 200 in DIPs or CSS pixels, even if the hardware is configured to display at a higher or lower resolution than usual. At a scale factor of 200%, if a 1x1 DIP or CSS pixel maps to a 1x1 physical pixel in 100%, it will map to a 2x2 physical pixel square.




                I know that Pixels per inch are literal, they are the number of pixels in an inch, but how do they relate to DIPs? A totally separate measurement?




                CSS does not use PPI; it only uses DPI. Section 6.4 of css-values-3 lists the following units:




                dpi

                Dots per inch.



                dpcm

                Dots per centimeter.



                dppx

                Dots per px unit.



                The <resolution> unit represents the size of a single "dot" in a graphical representation by indicating how many of these dots fit in a CSS in, cm, or px.




                For the purposes of CSS and Media Queries, a single "dot" always corresponds to a single physical pixel, never a DIP or CSS pixel, hence the dppx unit. For example, a scale factor of 200% or device pixel ratio (non-standard) of 2.0 is equivalent to 2 dppx.






                share|improve this answer















                I know hardware pixels and physical pixels are the smallest unit, and that density independent pixels map to actual hardware pixels via a device pixel ratio and they are used to make the viewing experience more consistent. Does this mean that the device independent pixels I'm seeing are the same thing?



                Further, I read that the browser reports viewport width in CSS pixels, are these and DIPs the same thing?




                Yes on both counts. For example, an element with height: 200px; width: 200px is always 200 by 200 in DIPs or CSS pixels, even if the hardware is configured to display at a higher or lower resolution than usual. At a scale factor of 200%, if a 1x1 DIP or CSS pixel maps to a 1x1 physical pixel in 100%, it will map to a 2x2 physical pixel square.




                I know that Pixels per inch are literal, they are the number of pixels in an inch, but how do they relate to DIPs? A totally separate measurement?




                CSS does not use PPI; it only uses DPI. Section 6.4 of css-values-3 lists the following units:




                dpi

                Dots per inch.



                dpcm

                Dots per centimeter.



                dppx

                Dots per px unit.



                The <resolution> unit represents the size of a single "dot" in a graphical representation by indicating how many of these dots fit in a CSS in, cm, or px.




                For the purposes of CSS and Media Queries, a single "dot" always corresponds to a single physical pixel, never a DIP or CSS pixel, hence the dppx unit. For example, a scale factor of 200% or device pixel ratio (non-standard) of 2.0 is equivalent to 2 dppx.







                share|improve this answer














                share|improve this answer



                share|improve this answer








                edited Oct 20 '17 at 17:58









                Community

                11




                11










                answered Jan 26 '17 at 1:51









                BoltClock

                514k12711521191




                514k12711521191






























                    draft saved

                    draft discarded




















































                    Thanks for contributing an answer to Stack Overflow!


                    • Please be sure to answer the question. Provide details and share your research!

                    But avoid



                    • Asking for help, clarification, or responding to other answers.

                    • Making statements based on opinion; back them up with references or personal experience.


                    To learn more, see our tips on writing great answers.





                    Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


                    Please pay close attention to the following guidance:


                    • Please be sure to answer the question. Provide details and share your research!

                    But avoid



                    • Asking for help, clarification, or responding to other answers.

                    • Making statements based on opinion; back them up with references or personal experience.


                    To learn more, see our tips on writing great answers.




                    draft saved


                    draft discarded














                    StackExchange.ready(
                    function () {
                    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f41863545%2fphysical-pixels-vs-css-pixels-vs-device-independent-pixels-vs-density-independen%23new-answer', 'question_page');
                    }
                    );

                    Post as a guest















                    Required, but never shown





















































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown

































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown







                    Popular posts from this blog

                    What visual should I use to simply compare current year value vs last year in Power BI desktop

                    Alexandru Averescu

                    Trompette piccolo