{"id":1533,"date":"2026-09-06T09:13:00","date_gmt":"2026-09-06T13:13:00","guid":{"rendered":"https:\/\/www.xconvert.com\/blog\/?p=1533"},"modified":"2026-08-31T17:09:04","modified_gmt":"2026-08-31T21:09:04","slug":"how-gif-optimization-works","status":"publish","type":"post","link":"https:\/\/www.xconvert.com\/blog\/how-gif-optimization-works","title":{"rendered":"How GIF Optimization Actually Works: Palettes, Frames, Lossy"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">You drop a GIF into an \u201coptimizer,\u201d nudge a slider, and the file comes out 60% smaller \u2014 but nothing on screen tells you <em>what changed<\/em>. Fewer colors? Fewer frames? Some magic \u201ccompression\u201d? GIF optimization isn\u2019t magic; it\u2019s a handful of concrete mechanisms working on a file format finalized in 1989, plus one older trick to squeeze its ancient compression harder. This guide opens the hood on each lever \u2014 what it does to the bytes, whether it costs quality, and which control drives it \u2014 checked against the GIF89a specification and the gifsicle optimizer\u2019s own documentation.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p><strong>Quick answer:<\/strong> A GIF optimizer pulls three real levers. <strong>(1) Palette:<\/strong> GIF stores each pixel as an index into a table of at most <strong>256 colors<\/strong>, so using fewer colors means fewer bytes per pixel <em>and<\/em> longer repeating runs for the compressor to catch. <strong>(2) Frames:<\/strong> an optimizer stores only the <em>changed<\/em> part of each frame (frame differencing \u2014 lossless) and can also <strong>drop<\/strong> whole frames (lossy). <strong>(3) Lossy GIF:<\/strong> GIF\u2019s LZW compression is lossless, so \u201clossy\u201d tools quietly nudge pixels to <em>similar<\/em> colors so LZW finds longer matches. Resolution (fewer pixels) is the fourth big lever. On xconvert they surface as the <strong>Colors<\/strong>, <strong>Drop Frames<\/strong>, <strong>Image quality (%)<\/strong> and <strong>Image resolution<\/strong> controls \u2014 which live under <strong>File Compression \u2192 Custom<\/strong>, because the compressor\u2019s default route is a size target instead.<\/p><\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">Jump to a section<\/h2>\n\n\n\n<ul class=\"wp-block-list\"><li><a href=\"#lzw\">First, the one thing every lever really feeds: LZW<\/a><\/li><li><a href=\"#palette\">Lever 1: the color palette<\/a><\/li><li><a href=\"#frames\">Lever 2: frame differencing vs. dropping frames<\/a><\/li><li><a href=\"#lossy\">Lever 3: \u201clossy GIF\u201d \u2014 bending a lossless codec<\/a><\/li><li><a href=\"#together\">Putting it together (and where resolution fits)<\/a><\/li><li><a href=\"#tool\">How the levers map to xconvert\u2019s GIF compressor<\/a><\/li><li><a href=\"#faq\">FAQ<\/a><\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"lzw\">First, the one thing every lever really feeds: LZW<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Every animated GIF\u2019s pixel data is squeezed with <strong>LZW<\/strong> \u2014 Lempel\u2013Ziv\u2013Welch, the dictionary compressor Terry Welch published in 1984 and that CompuServe baked into GIF in 1987. What LZW rewards is the key that makes all three levers stop looking arbitrary.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Per the GIF89a specification\u2019s Appendix F (\u201cVariable-Length-Code LZW Compression\u201d), the encoder scans the pixel values and <strong>builds a dictionary of patterns as it encounters them<\/strong>: each new run of pixels is added to a code table, and when that run repeats, the encoder emits one short code instead of the pixels. Codes grow from 9 up to a maximum of 12 bits. And it is <strong>lossless<\/strong> \u2014 LZW never discards information, it only finds and shortens <em>exact<\/em> repeats.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That is load-bearing: <strong>LZW only saves space on long, exactly-repeating runs of identical pixel values.<\/strong> A flat band of one color collapses to almost nothing; speckle where every pixel differs from its neighbor saves almost nothing. So here\u2019s the spine of the article \u2014 <em>almost every GIF optimization is a way to give LZW longer, more-exact runs to find, or to shrink how much data it runs over.<\/em><\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"palette\">Lever 1: the color palette<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">GIF is an <strong>indexed-color<\/strong> format. Instead of storing red\/green\/blue for every pixel, it stores a small color table \u2014 the palette \u2014 and each pixel is just an <strong>index<\/strong> pointing at one row of that table. Per the spec, the table holds at most <strong>256 entries<\/strong>, because the index is 8 bits (2\u2078). A file can carry one <strong>Global Color Table<\/strong> for the whole animation, or a <strong>Local Color Table<\/strong> attached to an individual frame.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Reducing the palette shrinks the file two ways:<\/p>\n\n\n\n<ol class=\"wp-block-list\"><li><strong>Directly<\/strong> \u2014 a smaller palette can be described with fewer bits per pixel.<\/li><li><strong>Indirectly, and this is the bigger effect<\/strong> \u2014 quantizing down to, say, 64 colors forces neighboring pixels that were <em>almost<\/em> the same color onto the <em>same<\/em> index, manufacturing exactly the long, identical runs LZW rewards. That\u2019s why color reduction usually shrinks a file more than the raw bit-count math predicts.<\/li><\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">A <strong>color-quantization<\/strong> step (median-cut and similar algorithms) picks the most representative colors and maps every pixel to its nearest survivor. Optional <strong>dithering<\/strong> then scatters two palette colors in a fine checker to fake a shade the palette no longer holds.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The catch follows straight from the LZW rule above: <strong>dithering deliberately makes neighboring pixels differ<\/strong> to fool the eye \u2014 the opposite of the identical runs LZW needs. So turning dithering up can <em>increase<\/em> the file even as it hides banding; it\u2019s a <strong>quality<\/strong> tool, not a size tool. On xconvert this lever is the <strong>Colors<\/strong> control (\u201cBy Color Reduction + Dither\u201d), under <strong>File Compression \u2192 Custom<\/strong>; its <strong>Dither<\/strong> toggle is off by default, for exactly this reason.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"frames\">Lever 2: frame differencing vs. dropping frames<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Two very different things get lumped together as \u201cframe optimization.\u201d Separating them is where most explanations go fuzzy.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Frame differencing (lossless).<\/strong> GIF89a doesn\u2019t require every frame to repaint the whole canvas: each image carries its own position and size (Image Left\/Top Position, Width, Height), so a frame can redraw just a small rectangle. It also supports a <strong>transparent index<\/strong> \u2014 transparent pixels are simply not drawn (\u201cthe corresponding pixel of the display device is not modified\u201d) \u2014 and a <strong>disposal method<\/strong> governing what stays on screen between frames. An optimizer uses all three: it diffs each frame against the previous one, stores <strong>only the rectangle that changed<\/strong>, and marks the untouched pixels transparent so they inherit what was already there. On a screen recording where only a cursor moves, that turns most of every frame into one giant transparent run \u2014 which compresses to almost nothing. gifsicle documents exactly this as its optimization levels: <strong>-O1<\/strong>, \u201cstore only the changed portion of each image,\u201d and <strong>-O2<\/strong>, which adds \u201cuse transparency.\u201d It\u2019s <strong>lossless<\/strong> \u2014 the animation looks identical \u2014 and it\u2019s housekeeping a good optimizer does <em>automatically<\/em>, not a slider you set.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Frame dropping (lossy).<\/strong> The other lever throws frames away: keep every 2nd or 3rd frame and lengthen the survivors\u2019 display time. Fewer stored images means proportionally fewer bytes, but you spend motion smoothness \u2014 fast action turns choppy, while slow pans and talking heads survive fine. This one <em>is<\/em> a control you set: on xconvert, <strong>Drop Frames<\/strong> under <strong>File Compression \u2192 Custom<\/strong>, whose <strong>Frames To Drop<\/strong> dropdown runs from <em>Every 2nd frame<\/em> to <em>Every 10th<\/em> and starts on <strong>Every 3rd frame<\/strong>.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"lossy\">Lever 3: \u201clossy GIF\u201d \u2014 bending a lossless codec<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The paradox that trips people up: LZW is lossless \u2014 it can\u2019t throw detail away \u2014 yet tools advertise \u201clossy GIF.\u201d How?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">They don\u2019t touch LZW; they change the <strong>pixels fed into it<\/strong>. A normal encoder, building its dictionary, looks for the longest run of pixels that <em>exactly<\/em> matches something it has already seen. A <strong>lossy<\/strong> encoder relaxes \u201cexactly\u201d to <strong>\u201csimilar enough\u201d<\/strong>: if nudging one pixel to a neighboring palette color lets the run continue, it makes that swap, then dithers to disguise the small distortion. Longer runs \u2192 better LZW \u2192 smaller file. As Kornel Lesi\u0144ski, who wrote the widely used lossy GIF encoder, puts it, the lossy encoder \u201cpicks the longest string of pixels that\u2019s \u2018similar enough\u2019 to pixels in the image (plus some magic to hide the distortions with dithering).\u201d<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">What it costs is a little noise; what it buys is typically a <strong>30\u201350%<\/strong> smaller animated GIF, per the lossy encoder\u2019s own figures. gifsicle exposes it as the <strong>\u2013lossy<\/strong> option \u2014 \u201calter image colors to shrink output file size at the cost of artifacts and noise,\u201d with a lossiness number (default 20) where higher means smaller and noisier. On xconvert this lever is the <strong>Image quality (%)<\/strong> slider under <strong>File Compression \u2192 Custom<\/strong>, which starts at <strong>80%<\/strong> \u2014 \u201ca balanced lossy LZW setting,\u201d as the tool page puts it.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"together\">Putting it together (and where resolution fits)<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">There\u2019s a fourth lever, often the biggest: <strong>resolution<\/strong>. A GIF\u2019s data is roughly <em>pixels-per-frame \u00d7 frames<\/em>, and pixel count scales with <strong>area<\/strong> \u2014 so halving width and height keeps only a quarter of the pixels, a quarter as many indices for LZW to store. It\u2019s \u201clossy\u201d only in that you discard detail you may not be displaying. Here\u2019s every mechanism in one view:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>Mechanism<\/th><th>What it changes in the bytes<\/th><th>Lossless?<\/th><th>xconvert control<\/th><\/tr><\/thead><tbody><tr><td><strong>Palette reduction<\/strong><\/td><td>Fewer color-table entries; more identical runs<\/td><td>Lossy (color)<\/td><td>Colors (Custom)<\/td><\/tr><tr><td><strong>Frame differencing<\/strong><\/td><td>Store only the changed region + transparency<\/td><td><strong>Lossless<\/strong><\/td><td>Automatic<\/td><\/tr><tr><td><strong>Frame dropping<\/strong><\/td><td>Fewer stored frames<\/td><td>Lossy (motion)<\/td><td>Drop Frames (Custom)<\/td><\/tr><tr><td><strong>Lossy LZW<\/strong><\/td><td>Pixels nudged to lengthen LZW matches<\/td><td>Lossy (noise)<\/td><td>Image quality (%) (Custom)<\/td><\/tr><tr><td><strong>Resolution<\/strong><\/td><td>Fewer pixels per frame<\/td><td>Lossy (detail)<\/td><td>Image resolution (Custom)<\/td><\/tr><tr><td><strong>All of the above, aimed at a number<\/strong><\/td><td>Combinations searched until the output fits a ceiling you name<\/td><td>Lossy (mixed)<\/td><td>Max file size \u2192 Size limit<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">The lossless mechanisms (frame differencing, trimming dead frames, resizing) reorganize data so LZW works harder; the lossy ones (palette, frame dropping, lossy LZW) remove information \u2014 so lean on the lossless ones first.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Note the last row, because it changes how you <em>drive<\/em> the tool. Every control in the first five rows is a knob you set and then measure. The compressor\u2019s default route inverts that: you state the size you need and it works the knobs, which is why those five now sit behind a <strong>Custom<\/strong> switch rather than greeting you on arrival.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For <em>why<\/em> a GIF is so oversized to begin with, see <a href=\"https:\/\/www.xconvert.com\/blog\/why-is-my-gif-file-so-big\/\">why is my GIF file so big<\/a>; for how hard to pull each lever without visibly hurting the image, see <a href=\"https:\/\/www.xconvert.com\/blog\/make-a-gif-smaller-without-losing-quality\/\">make a GIF smaller without losing quality<\/a>.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"tool\">How the levers map to xconvert\u2019s GIF compressor<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The <a href=\"https:\/\/www.xconvert.com\/compress-gif\">xconvert GIF compressor<\/a> offers each lever as a direct control \u2014 but it doesn\u2019t open on them. <strong>File Compression<\/strong> greets you with <strong>Max file size<\/strong>, the aim-at-a-number route; <strong>Custom<\/strong> is the switch that reveals the knobs this article has been describing.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Route A \u2014 name the size, let it search the levers.<\/strong><\/p>\n\n\n\n<ol class=\"wp-block-list\"><li>Open <a href=\"https:\/\/www.xconvert.com\/compress-gif\">xconvert.com\/compress-gif<\/a> and click <strong>Upload<\/strong> to add your GIF (from your computer, Google Drive, or Dropbox).<\/li><li><strong>File Compression<\/strong> is already on <strong>Max file size<\/strong>. Set the <strong>Size limit<\/strong> dropdown: <strong>Custom size %<\/strong> (the default, capping output at a percentage of the original \u2014 75% to start), <strong>Custom size value<\/strong> for a typed number in B \/ KB \/ MB, or a <strong>Discord (10 MB max)<\/strong> \/ <strong>Email (25 MB max)<\/strong> \/ <strong>Forum (2 MB max)<\/strong> preset.<\/li><li>Click <strong>Compress<\/strong>, then download. The output comes back at or under the ceiling where the content allows \u2014 best-effort, not a guaranteed landing size, so a very aggressive ask on a large source gets as close as the format permits.<\/li><\/ol>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Route B \u2014 pull the levers yourself.<\/strong> Switch <strong>File Compression<\/strong> to <strong>Custom<\/strong> and the four groups appear:<\/p>\n\n\n\n<ol class=\"wp-block-list\"><li><strong>Colors<\/strong> \u2192 <strong>By Color Reduction + Dither<\/strong> shrinks the palette \u2014 <a href=\"#palette\">Lever 1<\/a>. The <strong>Color Palette Size<\/strong> dropdown starts at 128; the <strong>Dither<\/strong> toggle starts off.<\/li><li><strong>Drop Frames<\/strong> \u2014 the lossy frame lever \u2014 opens already switched on with <strong>Every 3rd frame<\/strong> picked in <strong>Frames To Drop<\/strong> (the alternative for this group is ORIGINAL, keeping every frame).<\/li><li><strong>Image quality (%)<\/strong> \u2014 the \u201clossy LZW\u201d lever \u2014 starts at <strong>80<\/strong>.<\/li><li><strong>Image resolution<\/strong> takes a <strong>Resolution Percentage<\/strong>, a <strong>Preset Resolution<\/strong>, or a <strong>Width<\/strong> \/ <strong>Height<\/strong> with aspect ratio kept.<\/li><li>Click <strong>Compress<\/strong>, then download. Custom mode applies exactly what you set and doesn\u2019t chase a number, so read the output size and pull a lever harder \u2014 or hand the problem back to <strong>Max file size<\/strong>.<\/li><\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">Your file is processed on our servers and deleted automatically a few hours later \u2014 nothing stays around.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"faq\">FAQ<\/h2>\n\n\n\n<h5 class=\"wp-block-heading\">How does a GIF optimizer actually make the file smaller?<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">It works on GIF\u2019s <strong>LZW compression, which only shrinks long, exactly-repeating runs of identical pixels<\/strong>. Optimizers manufacture more of those runs and cut how much data there is: <strong>reduce the color palette<\/strong> (more pixels share an index), <strong>frame differencing<\/strong> (store only the changed part of each frame, the rest transparent), <strong>drop frames<\/strong>, <strong>lower resolution<\/strong>, and <strong>lossy encoding<\/strong> (nudge pixels to similar colors so runs get longer). Palette, frames, and lossy are the three core levers; resolution is the fourth.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\">If GIF\u2019s compression is lossless, what is \u201clossy GIF\u201d?<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">GIF\u2019s LZW is genuinely lossless. \u201cLossy GIF\u201d doesn\u2019t change LZW \u2014 it changes the pixels <em>before<\/em> they reach it. A lossy encoder accepts a run that\u2019s <strong>\u201csimilar enough\u201d<\/strong> rather than an exact match, swapping a pixel for a neighboring palette color when that lengthens a match, then dithers to hide it \u2014 commonly <strong>30\u201350% smaller<\/strong> at the cost of a little noise. On xconvert it\u2019s the <strong>Image quality (%)<\/strong> slider, which appears once you switch <strong>File Compression<\/strong> to <strong>Custom<\/strong> and starts at 80%.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\">What is frame differencing (transparency optimization)?<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">It\u2019s the <strong>lossless<\/strong> frame lever: instead of storing every frame whole, the optimizer stores only the rectangle that changed and marks the unchanged pixels <strong>transparent<\/strong> to inherit what\u2019s already on screen. GIF supports this via per-frame position\/size, a transparent index, and a disposal method; gifsicle calls it levels <strong>-O1\/-O2<\/strong>. On a static-background clip like a screen recording it\u2019s a huge, quality-free win applied automatically.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\">Does reducing the number of colors really shrink a GIF, and why?<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Yes \u2014 two ways.<\/strong> A smaller palette needs fewer bits to describe, but the bigger effect is that quantizing to fewer colors makes neighboring pixels collapse onto the <strong>same index<\/strong>, creating the long identical runs LZW compresses best. That\u2019s why 256 \u2192 64 colors often shrinks a file more than the raw math predicts \u2014 though photos and gradients start to show banding.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\">Why does turning on dithering sometimes make the GIF bigger?<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">Because dithering deliberately <strong>scatters different palette colors<\/strong> to fake shades the palette lacks \u2014 and that speckle is the opposite of the repeating runs LZW needs. So dithering is a <strong>quality<\/strong> tool (it hides banding), not a size tool, and paired with color reduction it can reverse the savings. Reduce colors for size; add dithering only when appearance demands it.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\">Is optimizing a GIF lossless or does it degrade the image?<\/h5>\n\n\n\n<p class=\"wp-block-paragraph\">It\u2019s a mix. <strong>Frame differencing, trimming dead frames, and resizing to display size are effectively lossless<\/strong> to the viewer. <strong>Palette reduction, frame dropping, and lossy encoding trade quality<\/strong> \u2014 color fidelity, motion smoothness, or a little noise. The reliable approach: exhaust the lossless mechanisms first, then spend the lossy ones only as far as your content tolerates.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Sources<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><em>Last verified 2026-08-31.<\/em><\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><a href=\"https:\/\/www.w3.org\/Graphics\/GIF\/spec-gif89a.txt\">W3C \u2014 GIF89a specification<\/a> \u2014 the 256-entry color table (8-bit index), Global vs. Local Color Tables, per-frame position\/size (sub-region redraw), the transparent index and disposal method, and Appendix F, \u201cVariable-Length-Code LZW Compression.\u201d<\/li><li><a href=\"https:\/\/www.lcdf.org\/gifsicle\/man.html\">gifsicle man page (Eddie Kohler, LCDF)<\/a> \u2014 optimization levels (-O1 \u201cstore only the changed portion,\u201d -O2 \u201cand use transparency,\u201d -O3) and the <code>--lossy<\/code> option (\u201calter image colors to shrink output file size at the cost of artifacts and noise\u201d; default lossiness 20).<\/li><li><a href=\"https:\/\/kornel.ski\/lossygif\">Kornel Lesi\u0144ski \u2014 \u201cLossy GIF compressor\u201d<\/a> \u2014 how lossy LZW works (the longest \u201csimilar enough\u201d run plus dithering) and the 30\u201350% size-reduction figure.<\/li><li>Welch, T. A. (1984). \u201cA Technique for High-Performance Data Compression.\u201d <em>IEEE Computer<\/em> 17(6):8\u201319 \u2014 the original description of the LZW dictionary algorithm GIF adopted in 1987.<\/li><li><a href=\"https:\/\/www.xconvert.com\/compress-gif\">xconvert GIF compressor<\/a> \u2014 live tool; verified that <strong>File Compression<\/strong> opens on <strong>Max file size<\/strong> with a <strong>Size limit<\/strong> dropdown (Custom size % at 75%, Custom size value in B\/KB\/MB, and Discord\/Email\/Forum presets), and that switching to <strong>Custom<\/strong> reveals Colors (\u201cBy Color Reduction + Dither\u201d, palette 128, dither off), Drop Frames (Frames To Drop starting at \u201cEvery 3rd frame\u201d), Image quality (%) (default 80%, \u201ca balanced lossy LZW setting\u201d), and Image resolution.<\/li><\/ul>\n","protected":false},"excerpt":{"rendered":"<p>What a GIF optimizer actually does: the three mechanisms behind a smaller GIF \u2014 palette reduction, frame differencing, and lossy LZW.<\/p>\n","protected":false},"author":3,"featured_media":1532,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,14],"tags":[],"class_list":["post-1533","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-how-to-guides","category-tools"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.9 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>How GIF Optimization Actually Works: Palettes, Frames, Lossy<\/title>\n<meta name=\"description\" content=\"What a GIF optimizer actually does: the three mechanisms behind a smaller GIF \u2014 palette reduction, frame differencing, and lossy LZW.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.xconvert.com\/blog\/how-gif-optimization-works\" 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