{"id":81072,"date":"2026-09-29T09:15:27","date_gmt":"2026-09-29T09:15:27","guid":{"rendered":"https:\/\/www.arimetrics.com\/?post_type=encyclopedia&#038;p=81072"},"modified":"2026-09-29T09:16:43","modified_gmt":"2026-09-29T09:16:43","slug":"avif","status":"publish","type":"encyclopedia","link":"https:\/\/www.arimetrics.com\/en\/digital-glossary\/avif","title":{"rendered":"AVIF"},"content":{"rendered":"<p><img decoding=\"async\" class=\"boxpad alignright wp-image-81073 size-full\" src=\"https:\/\/www.arimetrics.com\/wp-content\/uploads\/2026\/09\/avif-square.png\" style=\"margin-top:0;\" alt=\"AVIF as an AV1-based image format\" width=\"300\" height=\"300\" srcset=\"https:\/\/www.arimetrics.com\/wp-content\/uploads\/2026\/09\/avif-square.png 300w, https:\/\/www.arimetrics.com\/wp-content\/uploads\/2026\/09\/avif-square-150x150.png 150w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/> <strong>Definition:<\/strong> <strong>AVIF<\/strong> is a raster image format that stores AV1-encoded data inside a HEIF-based structure. Its name stands for <em>AV1 Image File Format<\/em>, it commonly uses the <code>.avif<\/code> extension, and its MIME type is <code>image\/avif<\/code>.<\/p>\n<p>The format supports <strong>flexible compression<\/strong>, transparency, still images, and sequences. It can also represent SDR, HDR, and wide color gamut content. These capabilities do not guarantee a smaller file or a better image by themselves: results depend on the content, encoder, and settings.<\/p>\n\n<h2>How AVIF Works<\/h2>\n<p>AVIF uses a <strong>HEIF container<\/strong>, which is based on the ISO Base Media File Format. The file stores AV1-encoded image items or sequences, together with properties describing dimensions, orientation, color, relationships between items, and other data needed to interpret them.<\/p>\n<p>A still image is usually stored as an <strong>AV1 image item<\/strong>. Sequences can gather multiple frames to create animations. The container can also associate a color image with auxiliary items such as an alpha channel or a depth map.<\/p>\n<p>The <a href=\"https:\/\/aomediacodec.github.io\/av1-avif\/\" target=\"_blank\" rel=\"noopener\">AVIF specification<\/a> defines profiles and restrictions to improve interoperability between encoders and readers. The extension does not reveal every internal feature: two AVIF files may use different color depths, subsampling, compression, or structure and require <strong>different capabilities<\/strong> from the software opening them.<\/p>\n<h2>AVIF Compression<\/h2>\n<p>AV1 uses prediction, transforms, and other techniques to reduce spatial redundancy. AVIF can use lossy compression for small files or lossless mode when source values must be preserved. The <strong>main options<\/strong> include:<\/p>\n<ul>\n<li><strong>Quality:<\/strong> Controls the balance between visual fidelity and file size.<\/li>\n<li><strong>Speed:<\/strong> More exhaustive analysis may improve efficiency but increases encoding time.<\/li>\n<li><strong>Subsampling:<\/strong> Reducing chroma information can decrease size, although it does not suit every graphic.<\/li>\n<li><strong>Bit depth:<\/strong> The format can use 8, 10, or 12 bits per component depending on the profile and tools.<\/li>\n<\/ul>\n<p>AVIF may outperform older formats in certain comparisons, especially for photographs, but there is no fixed saving that applies to every image. File size should be compared at <strong>equivalent quality<\/strong>, while fine details, text, edges, noise, and gradients should be reviewed before selecting parameters.<\/p>\n<h2>Color in AVIF<\/h2>\n<p>The format can represent <strong>SDR and HDR<\/strong>, monochrome images, different color spaces, and wide gamuts. Container metadata and properties indicate how values should be interpreted, while 10-bit or 12-bit depth reduces the risk of banding in demanding gradients.<\/p>\n<p>For <strong>consistent results<\/strong>, the entire pipeline must correctly handle profiles, transfer characteristics, and color conversion. A file technically capable of storing HDR may lose that advantage if the editor, optimizer, CMS, or display transforms the data incorrectly.<\/p>\n<h2>AVIF Transparency<\/h2>\n<p>AVIF supports an <strong>alpha channel<\/strong> for fully or partially transparent pixels. This channel can be stored as an auxiliary item linked to the main image and can have its own encoding parameters.<\/p>\n<p>Transparency is useful for cutout products, illustrations, and elements placed over <strong>changing backgrounds<\/strong>. Edges should be checked on light and dark backgrounds because unsuitable compression, subsampling, or alpha handling may create halos or visible changes.<\/p>\n<h2>Comparison With Other Formats<\/h2>\n<p>The choice should reflect image type, workflow, and required compatibility. The <strong>common differences<\/strong> are:<\/p>\n<ul>\n<li><strong><a href=\"https:\/\/www.arimetrics.com\/en\/digital-glossary\/jpg\">JPG<\/a>:<\/strong> It retains very broad historical compatibility and fast encoding but does not support transparency, HDR, or animation.<\/li>\n<li><strong><a href=\"https:\/\/www.arimetrics.com\/en\/digital-glossary\/png\">PNG<\/a>:<\/strong> It preserves pixels losslessly and works well for screenshots or graphics; AVIF may be smaller, but fidelity must be tested.<\/li>\n<li><strong><a href=\"https:\/\/www.arimetrics.com\/en\/digital-glossary\/webp\">WebP<\/a>:<\/strong> It also offers lossy and lossless compression, alpha, and animation. It usually provides faster encoding and a longer support history.<\/li>\n<li><strong><a href=\"https:\/\/www.arimetrics.com\/en\/digital-glossary\/svg\">SVG<\/a>:<\/strong> It is vector-based and preferable for shapes, icons, or logos that must scale sharply.<\/li>\n<\/ul>\n<p>AVIF can store sequences and compete with GIF or animated WebP, although video is more appropriate for long content, audio, or playback controls. A <strong>master source<\/strong> should also be retained to prevent accumulated degradation from repeated conversion between compressed formats.<\/p>\n<h2>AVIF Optimization<\/h2>\n<p>Optimization should consider file size, quality, and encoding cost. To improve <a href=\"https:\/\/www.arimetrics.com\/en\/digital-glossary\/wpo\">WPO<\/a>, recommended <strong>optimization steps<\/strong> include:<\/p>\n<ul>\n<li><strong>Adjust dimensions:<\/strong> Generate each image at the size needed for its presentation.<\/li>\n<li><strong>Create variants:<\/strong> Combine different widths with <code>srcset<\/code> and <code>sizes<\/code>.<\/li>\n<li><strong>Test parameters:<\/strong> Compare quality, speed, bit depth, and subsampling for each image type.<\/li>\n<li><strong>Keep fallback:<\/strong> Use <code>&lt;picture&gt;<\/code> when part of the audience or system needs WebP, JPG, or PNG.<\/li>\n<li><strong>Measure results:<\/strong> Review transferred bytes, decoding time, visible quality, and metrics such as LCP.<\/li>\n<\/ul>\n<p>Support is broad in modern browsers, but editors, libraries, CDNs, content management systems, applications, and bots should also be checked. A smaller variant does not automatically improve experience if it takes too long to generate, decodes poorly, or arrives without <strong>reserved dimensions<\/strong> that prevent layout shifts.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>AVIF is an AV1-based image format with advanced compression, transparency, and HDR. Learn how it works, when to use it, and how to optimize it.<\/p>\n","protected":false},"author":6,"featured_media":81075,"template":"","encyclopedia-tag":[1340],"class_list":["post-81072","encyclopedia","type-encyclopedia","status-publish","has-post-thumbnail","hentry","encyclopedia-tag-visual-creation"],"_links":{"self":[{"href":"https:\/\/www.arimetrics.com\/en\/wp-json\/wp\/v2\/encyclopedia\/81072","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.arimetrics.com\/en\/wp-json\/wp\/v2\/encyclopedia"}],"about":[{"href":"https:\/\/www.arimetrics.com\/en\/wp-json\/wp\/v2\/types\/encyclopedia"}],"author":[{"embeddable":true,"href":"https:\/\/www.arimetrics.com\/en\/wp-json\/wp\/v2\/users\/6"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.arimetrics.com\/en\/wp-json\/wp\/v2\/media\/81075"}],"wp:attachment":[{"href":"https:\/\/www.arimetrics.com\/en\/wp-json\/wp\/v2\/media?parent=81072"}],"wp:term":[{"taxonomy":"encyclopedia-tag","embeddable":true,"href":"https:\/\/www.arimetrics.com\/en\/wp-json\/wp\/v2\/encyclopedia-tag?post=81072"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}