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description=Look up HTML5, CSS3, etc features, know if they are ready for use, and if so find out how you should use them – with polyfills, fallbacks or as they are.;

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use, with, css, polyfill, html, api, fallback, caution, avoid, input, type, box, iframe, media, text, html5, and, features, image, border, shadow, dom, events, font, elements, search, position, svg, web, js, you, please, the, new, shiny, responsibly, explore, audio, background, options, radius, reflection, sizing, calc, canvas, classlist, contenteditable, cors, animations, filters, css3, colors, datalist, dataset, details, summary, dialog, drag, drop, ecmascript, above, eventsource, server, sent, exclusions, fetch, file, filesystem, filewriter, fit, content, flexbox, face, feature, settings, form, validation, formdata, fullscreen, geolocation, gradients, grids, history, hyphens, sandbox, seamless, srcdoc, img, srcset, indexeddb, color, date, number, range, placeholder, interaction, json, localstorage, masks, matchmedia, queries, menu, meter, microdata, multicolumn, multiple, backgrounds, offline, ol, reversed, opacity, paged, picture, pointer, fixed, sticky, postmessage, progress, pseudo, regions, rem, unit, requestanimationframe, ruby, selectors, style, scoped, supports, overflow, stroke, track, transforms, transitions, vibration, video, viewport, units, vh, vw, vmin, vmax, components, workers, webgl, webp, websockets, websql, db, no, items, met, your, when, sunset, ie8, support, can,

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old browsers be aware about how the background image will be displayed without these options view browser share edit this info gtie8 fallback border image use with fallback css all main browsers support this unprefixed you should let this fall back to either a normal solid border or no border at all depending on whether a border is essential for readability we recommend that you avoid polyfills there were some syntax changes requiring the fill keywords that may catch you off guard david baron s border image post describes the best course of action view browser share edit this info fallback prefixes border radius use css border radius can be safely used without a prefix for all modern browsers and gracefully renders rectangles when not supported view browser share edit this info box reflection avoid css the box reflect property has never been part of any css specification certain presentations that are possible with webkit box reflect will be possible using css filters you should avoid using webkit only box reflections learn more edit this info none box shadow use css box shadows can be applied safely without prefixes view browser share edit this info prefixes box sizing use css supported in all major browsers see box sizing border box ftw if you want to set box sizing border box safely as default behavior view browser share edit this info gtie7 border box calc use with fallback css all browsers support calc unprefixed but do note that it can have a big impact on the layout and the consequent breaking of your design on unsupported browsers you should use it with a fallback declaration so it doesn t break on browsers which don t support it width 500px older browsers width calc 50 20px view browser share edit this info fallback canvas use with polyfill html canvas is definitely good to go for modern browsers if you want to support internet explorer 8 and below explorercanvas and flashcanvas can be helpful in providing support for most canvas features however due to the complex nature of native canvas implementations developers should be aware that the polyfills for canvas are not simple drop in solutions in some cases for example both explorercanvas and flashcanvas may have difficulties handling the commonly used drawimage method flashcanvas cannot be passed the bitmap data from a dom based image object and therefore has to re request the asset in the flash player causing undesired latency and flickering developers should be careful when handling image data and ensure thorough testing due to the unreliability and technical limitations of these features in the polyfills that isn t to say canvas shouldn t be used if cross browser compatibility is a concern existing polyfills are more than capable of rendering simpler bitmaps such as charts graphs visualizations and even starfields for these uses and many more canvas is highly encouraged recommended polyfills flashcanvas explorercanvas view browser share edit this info gtie8 polyfill classlist use with polyfill api classlist is well supported nowadays but expect incomplete support in ie10 11 and opera mobile see caniuse notes recommended polyfills classlist js view browser share edit this info polyfill gtie9 nooldmobile contenteditable use html go for it every browser supports the contenteditable attribute ie already supports this attribute since ie5 5 learn more edit this info none cors use with polyfill html cors or cross origin resource sharing enables a few things but most notably cross domain ajax all non ie browsers have support for cors ie8 introduced xdomainrequest so really only ie7 needs help with cross domain files consider the flxhr polyfill or you can fall back to using a simple proxy recommended polyfills flxhr requires crossdomain xml view browser share edit this info polyfill css animations use css animations are supported unprefixed in every major browser in order to provide support for legacy browsers either use animations only to provide non essential aesthetic enhancements or use feature detection to provide an alternative experience for browsers that do not support this feature view browser share edit this info css filters caution css filters are supported by edge 13 and firefox 35 unprefixed and in safari 6 opera 15 and chrome 18 with the webkit prefix if you really need full browser support use polyfilter which supports translates to emulates filters on chrome 20 safari 6 firefox 4 ie 6 9 but not ie 10 ios 6 safari and chrome and firefox 4 on mobile recommended polyfills polyfilter a css filters polyfill learn more edit this info prefixes css3 colors use with fallback css if you found yourself wanting to use papayawhip or goldenrod or indianred as your colors of choice do feel free you have to specify a fallback color for ie 8 users use the hsl hsla and rgba functions with more caution as they may not be supported on older browsers view browser share edit this info fallback gtie8 datalist use with polyfill html datalist enables autocomplete combo boxes it can be polyfilled for ie 9 and safari with the scripts below though they have varying levels of support for the full feature you can also use a graceful fallback if you choose not to polyfill please make sure to check caniuse regarding partial support even in modern browsers recommended polyfills datalist polyfill relevant dropdowns view browser share edit this info polyfill gtie9 nomobile dataset use with fallback api elem dataset is unsupported in internet explorer 10 and older mobile browsers using data attributes will be totally fine in all browsers but instead of using elem dataset foo just use elem getattribute data foo a polyfill is available if you want terser syntax recommended polyfills html5 dataset support view browser share edit this info fallback gtie10 nooldmobile details summary use with polyfill html use the details and optionally the summary element if you intend to show a summary which when clicked reveals detailed information currently not supported in any version of internet explorer or edge without polyfill non supporting browsers will fall back to displaying the element in the opened state recommended polyfills details polyfill learn more edit this info polyfill dialog caution with polyfill html the dialog element can be used to create popup dialogs or modal dialogs for web applications and is part of html 5 1 in its modal mode it blocks all access to content behind the front most dialog the majority of google s polyfill goes towards preventing the browser from gaining focus or accessing content behind the dialog you should consider that the preventative measures taken by the polyfill are not exhaustive as they are not implemented natively supported in chrome 37 and opera 24 tracked for firefox recommended polyfills dialog polyfill view browser share edit this info polyfill dom caution with polyfill api a large subset of the dom can currently be correctly shimmed however the current shims are not fully tested and are missing some features experimentally use with caution until the shim implementations have matured recommended polyfills es5 dom shim dom shim view browser share edit this info polyfill drag n drop caution with polyfill api drag and drop has been standardized in html5 based on internet explorer s original implementation therefore it already has wide desktop support but many feel frustrated when using the api you may want to use jquery ui draggable or another javascript library to handle this for you meanwhile the proposed dropzone attribute will improve the situation as it gains browser support there is not much mobile support currently recommended polyfills dropfile filesaver jdataview view browser share edit this info polyfill nomobile ecmascript 6 and above use with polyfill js ecmascript version 6 was a major update of javascript that brought new features and lots of syntactical additions es6 was later renamed to es2015 to reflect the changes in the release cycle since 2015 there are yearly releases with smaller feature sets es6 is pretty well supported by the latest browsers you can check the es6 compatibility table for details about the latest versions if you have to support internet explorer or would like to use the latest ecmascript features you will have to use babel as a tool to compile newer syntax to es5 babel polyfill to polyfill new built in methods note you should use babel polyfill with babel preset env and the usebuiltins option so that it doesn t include the whole polyfill otherwise you can use core js directly to import just the polyfills you need to receive a better performance due to smaller javascript bundle files recommended polyfills babel polyfill core js learn more edit this info polyfill eventsource server sent events use with polyfill api server sent events are real time events emitted by the server and received by the browser the main difference to websockets is that server sent events work over regular http and can therefore be replicated entirely using javascript eventsource isn t available in any version of internet explorer and still under consideration for edge see mdn web docs for more details recommended polyfills eventsource polyfill view browser share edit this info polyfill exclusions avoid css exclusions are new and exciting but very much in flux active development to get an implementation out is on going but again please avoid using this until there are stable implementations in the wild learn more edit this info none fetch api use with polyfill api the fetch api is a replacement for the xmlhttprequest object it s relatively new and the browser support isn t great at the moment but github provides a nice polyfill that supports ie9 the api is accessible via the global window fetch function recommended polyfills fetch learn more edit this info polyfill file api use with polyfill api using the file api added to the dom in html5 it s now possible for web content to ask the user to select local files filereader pairs very well with drag n drop to allow for drag n drop file uploads and if neither of those features are present the fallback of providing an input type file is rather easy fully supported in chrome firefox opera safari 6 and ie 10 partially supported in safari 5 1 lacks filereader support filereader provides useful fallback based on flash jquery and jquery ui doesn t support readasbinaryfile moxie extracted from plupload actively maintained as of 2013 06 03 recommended polyfills filereader moxie view browser share edit this info prefixes polyfill filesystem filewriter api avoid with polyfill api filesystem api provides a method of reading and writing files to a sandboxed file system on the user s local file system supported only by chrome 18 with webkit prefix check out https caniuse com feat filesystem for a better understanding of the support idb filesystem js implements a polyfill using indexeddb as its underlying storage layer required support for indexdb means that it works only in firefox and chrome recommended polyfills idb filesystem js view browser share edit this info prefixes polyfill fit content avoid css fit content is a value of the css attribute width it is fully supported by chrome partial supported by firefox and safari and not supported by edge and internet explorer you should avoid using it since it is not fully supported by any browser except of chrome view browser share edit this info none flexbox use css go for it css tricks a complete guide to flexbox provides strong reference documentation for all properties and values additionally the flexbox docs at mdn are an excellent resource flexbox has a funny history the flexbox spec changed significantly through three major revisions chris coyier shares how to tell which flexbox you re looking at the current version is supported by all modern browsers if you need to support ie 10 however you can mix old and new flexbox for maximum browser support we recommend looking at the solved by flexbox solution playground and work with the following tools to iterate and find your layout and syntax flexbox playground and flexplorer flexbugs is another valuable resource to discover flexbox issues and cross browser workarounds view browser share edit this info gtie9 font face use css use google fonts for hundreds of free open source fonts optimized for the web font squirrel generator for fonts you have license for using as web fonts always reference several font formats woff2 is preferred followed by woff ttf otf if you have to support outdated browsers like old versions of ie and ios safari also add eot and svg font formats at css tricks you find a good article about a bullet proof way of serving web fonts if you have to be aware of loading speed take a look at a comprehensive guide to font loading strategies view browser share edit this info font feature settings use css edge internet explorer 10 firefox 4 and chrome 16 windows and linux only support low level control over font feature settings what this means is other browsers merely will not render the flourishes you seek many features available through the property may be extracted to separate properties in the future such as font variant ligatures please note that if you want the best support you can get you should use the webkit and the moz prefixes more at opentype features in web browsers learn more edit this info prefixes form validation use with polyfill html html5 has baked in clientside form validation and polyfills can enable this for legacy browsers as well using the defined html5 api for constraint validation may be a more maintainable direction than using a jquery validation plugin depending on your team when detecting this feature be aware of safari s half baked support it does support form validation but won t highlight invalid fields or present error messages recommended polyfills hyperform view browser share edit this info polyfill gtie9 formdata api caution api xmlhttprequest level 2 adds support for the new formdata interface which provides a way to easily construct a set of key value pairs representing form fields and their values and can be sent using the xmlhttprequest send method a formdata object can be constructed from an already existing form or created programmatically sending input values can easily be done already for instance the mootools framework has a toquerystring method that can create a query string from any element what s new with formdata is that it can send files var xhr new xmlhttprequest file document getelementbyid myfile fd new formdata fd append file name file xhr open post api file upload xhr send fd fileapi can also be used to send files but you need to construct the body of the xhr by hand and send it using the sendasbinary method which is only implemented in firefox this might also use a lot of memory since the whole content of the file must be read in memory in order to build the body whereas formdata sends packets view browser share 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