I run amankumar.ai on Next.js. Pages would load, layouts would appear, and React would do its thing, but something still felt slow. amankumar.ai The problem wasn’t that the page didn’t render. The problem was this: The page renders, but images stay blank for a moment. Then they drop in one by one. And the site doesn’t feel visually complete until later. The page renders, but images stay blank for a moment. Then they drop in one by one. And the site doesn’t feel visually complete until later. That gap, where placeholders sit there and images arrive late, is subtle, but once you notice it, you can’t unsee it. It makes the site feel heavier than it should. So I stopped guessing and looked at the boring part I’d been ignoring: image payloads. image payloads Why this keeps happening on modern sites (without anyone messing up) This problem shows up a lot more today, even on well-built sites, and it’s not because people are careless. A few things are happening at once: Design tools export big images by default Posters, UI mockups, and screenshots often come out as large PNGs. AI-generated images are heavy by nature High detail, high resolution, no concern for delivery size. Frameworks don’t change asset intent Next.js can optimize delivery, but if the source image is huge, it still has to download. Image bloat accumulates quietly No errors, no warnings, just slower visual completion over time. Design tools export big images by default Posters, UI mockups, and screenshots often come out as large PNGs. Design tools export big images by default AI-generated images are heavy by nature High detail, high resolution, no concern for delivery size. AI-generated images are heavy by nature Frameworks don’t change asset intent Next.js can optimize delivery, but if the source image is huge, it still has to download. Frameworks don’t change asset intent delivery Image bloat accumulates quietly No errors, no warnings, just slower visual completion over time. Image bloat accumulates quietly The result is exactly what I was seeing: the page loads, but images arrive last. Measuring the problem on amankumar.ai Before touching anything, I measured the image assets in the repo. They were a mix of: PNGs (most of them) some JPG/JPEGs different resolutions photos, posters, and UI graphics, all mixed together PNGs (most of them) some JPG/JPEGs different resolutions photos, posters, and UI graphics, all mixed together This is repo-level image weight, not “every page ships 83 MB.” But it clearly showed the root issue. I was carrying a lot of unnecessary image data, and the browser was paying for it. repo-level image weight The engineering question I cared about I didn’t want a clever setup. I wanted something: repeatable boring safe for mixed assets easy to re-run later repeatable boring safe for mixed assets easy to re-run later So the real question became: What’s the simplest image pipeline that’s correct most of the time? What’s the simplest image pipeline that’s correct most of the time? What’s the simplest image pipeline that’s correct most of the time? First principle: pixels matter more than formats Before debating PNG vs WebP vs AVIF, the biggest issue was pixel count. pixel count If an image is 2400px wide but is never rendered above ~800px, shipping the extra pixels is pure waste. So I made one hard rule: Cap the max dimension at 800px. If an image is larger, downscale it. If it’s smaller, leave it alone. Cap the max dimension at 800px. If an image is larger, downscale it. If it’s smaller, leave it alone. Cap the max dimension at 800px. This single decision removes a surprising amount of weight. Image formats: quality vs size (same perceived quality) Once dimensions are sane, format choice actually matters. Here’s the practical ranking when comparing images at roughly the same visual quality: AVIF genuinely compresses better than WebP in many cases. Why I didn’t standardize on AVIF (yet) This is important, because AVIF is genuinely impressive. is The reason I didn’t standardize on it is not quality. It’s practical browser support and operational safety. not quality practical browser support and operational safety According to current browser compatibility data: AVIF support is good, but not universal Some older browsers, embedded webviews, and edge cases still fall back poorly AVIF support is good, but not universal good Some older browsers, embedded webviews, and edge cases still fall back poorly You can see the current state clearly here: https://caniuse.com/?search=avif https://caniuse.com/?search=avif For this project, I didn’t want: extra format negotiation more fallbacks “why didn’t this image load on X device?” debugging extra format negotiation more fallbacks “why didn’t this image load on X device?” debugging So the decision wasn’t “AVIF is bad.” It was: WebP is the safest modern default today. AVIF can be layered later if needed. WebP is the safest modern default today. AVIF can be layered later if needed. WebP is the safest modern default today. The tricky part: photos vs UI/posters My repo wasn’t just photos. It had: UI graphics posters with text logos and illustrations UI graphics posters with text logos and illustrations If you treat everything like a photo and apply lossy compression everywhere, UI assets suffer: fuzzy text halos around edges cheap-looking posters fuzzy text halos around edges cheap-looking posters WebP helped here because it supports both lossy and lossless modes. both lossy and lossless modes The challenge was choosing between them without manual tagging. without manual tagging The simple rule that worked I used one clean signal: If the image has transparency (alpha), likely UI or graphic, use lossless WebP If it’s fully opaque, likely a photo, use lossy WebP (quality ~80) If the image has transparency (alpha), likely UI or graphic, use lossless WebP If the image has transparency (alpha) lossless WebP If it’s fully opaque, likely a photo, use lossy WebP (quality ~80) If it’s fully opaque lossy WebP Is this perfect? No. Is it correct often enough to automate safely? Yes. That single rule handled mixed assets without human intervention. Metadata: invisible weight Many images carry metadata: camera EXIF editing history embedded profiles camera EXIF editing history embedded profiles None of this helps a webpage load faster or look better. So I strip metadata unconditionally. Sometimes the savings are small; sometimes they’re large. Either way, it’s free. Sanity check on a very different repo To make sure this wasn’t a one-off, I ran the same script, unchanged, on another repo: promptsmint.com, an AI prompts library with only AI-generated images. same script, unchanged promptsmint.com Before optimization Before optimization 92 images 228.12 MB total 2.48 MB per image (avg) 92 images 228.12 MB total 228.12 MB total 2.48 MB per image (avg) 2.48 MB per image (avg) After optimization After optimization 92 images 4.28 MB total ~50 KB per image (avg) 92 images 4.28 MB total 4.28 MB total ~50 KB per image (avg) ~50 KB per image (avg) Result Result 98.0% reduction 223.84 MB saved 98.0% reduction 98.0% reduction 223.84 MB saved 223.84 MB saved Different site. Different content. Same outcome. That confirmed this wasn’t luck. It was just removing waste. The script I packaged the whole pipeline into a single script and hosted it here: https://gist.github.com/onlyoneaman/cb5dbd36ed351b02e46db13d74e6dbe2 https://gist.github.com/onlyoneaman/cb5dbd36ed351b02e46db13d74e6dbe2 It: finds all jpg/jpeg/png/webp outputs *-optimized.webp next to originals caps size at 800px strips metadata uses lossless WebP for transparent images uses lossy WebP for opaque images finds all jpg/jpeg/png/webp jpg/jpeg/png/webp outputs *-optimized.webp next to originals *-optimized.webp caps size at 800px 800px strips metadata uses lossless WebP for transparent images lossless WebP for transparent images uses lossy WebP for opaque images lossy WebP for opaque images No clever tricks. Just consistent rules. The actual outcome I didn’t magically make Next.js faster. What changed is simpler and more important: Images arrive earlier. Placeholders disappear sooner. Pages feel visually complete faster. Images arrive earlier. Placeholders disappear sooner. Pages feel visually complete faster. That was the slowness I was noticing, and this fixed it. Thanks for reading. If you found this useful, you can follow or connect with me here: x.com linkedin x.com linkedin
