Image Format Comparison

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Choosing the right image format affects page speed, visual quality, file size, and compatibility — sometimes by orders of magnitude. There is no single best format; each strikes a different balance between compression, quality, and browser support. This guide compares the formats you are likely to encounter on the modern web and tells you which to reach for in common situations.

JPG (JPEG)

JPG is a lossy format optimized for photographs. It excels at smoothly varying tones (skin, sky, foliage) and discards information that humans are less likely to notice. Compression is tunable from heavily compressed (small but visibly blocky) to near-lossless (large but pristine). JPG has no transparency support and degrades quickly on text, line art, and large flat color regions. Universally supported by every browser and operating system.

PNG

PNG is a lossless format with full alpha transparency. It is the right choice for screenshots, line art, icons, and any image where exact pixel fidelity matters. Compression is good but not as efficient as modern alternatives for photographs. PNG files for typical photos are several times larger than the equivalent JPG. PNG-8 (256-color palette) can produce very small files for icons but is rarely needed in 2026.

WebP

WebP is a modern format developed by Google that supports both lossy and lossless compression, plus transparency and animation. For photographs, WebP typically produces files 25–35% smaller than JPG at equivalent quality. For graphics with transparency, it usually beats PNG by 20–25%. Browser support is universal across modern engines (Chrome, Firefox, Safari, Edge). WebP is the safe modern default for new photographs intended for the web.

AVIF

AVIF is a newer format based on the AV1 video codec. It produces smaller files than WebP at the same visual quality — typically 30–50% smaller than JPG, and 20% smaller than WebP. It supports HDR, wide color gamut, and 10/12-bit color depths. Browser support is universal in 2026, but encoding is significantly slower than WebP, which can be a problem for high-volume image pipelines. Use AVIF when bandwidth matters more than encode time.

SVG

SVG is a vector format that describes images as paths, shapes, and text rather than pixels. It scales to any size without quality loss, supports interactivity and animation, and is typically very small for logos, icons, and illustrations. SVG is unsuitable for photographs because the file size grows enormously with detail. Use SVG for anything that originated in a vector tool (Illustrator, Figma, Inkscape) and stays as line art.

HEIC / HEIF

HEIC (the image variant of HEIF) is the default capture format for newer iPhones. It typically produces files about half the size of JPG at equivalent quality and supports 10-bit color, transparency, and image sequences. Browser support is limited — Safari supports HEIC, but Chrome and Firefox do not. For web delivery, convert HEIC to JPG, WebP, or AVIF first. Our Image Format Converter handles HEIC input directly in the browser.

Choosing a format quickly

  • Photograph for web delivery: WebP for safe modern default, AVIF if you can afford encode time.
  • Photograph for fallback compatibility: JPG.
  • Screenshot or UI mockup: PNG (or WebP lossless).
  • Logo, icon, or illustration: SVG.
  • Image needing transparency: PNG, WebP, or AVIF.
  • Image captured on iPhone: HEIC for archival, convert for web.

Resolution and density

On high-DPI displays, an image that would be 200 × 200 logical pixels needs to be served at 400 × 400 or 600 × 600 actual pixels to look sharp. The HTML 'srcset' attribute and 'sizes' attribute let you provide multiple resolutions; the browser picks the appropriate one. Without this, you either serve unnecessarily large files to low-DPI screens or blurry files to high-DPI ones.

Compression quality settings

Most encoders expose a quality parameter from 0 to 100. For JPG, 75–85 is usually indistinguishable from the original for typical photographs; below 60 starts showing artifacts. For WebP, 75 is a good default; 80–85 is near-lossless. For AVIF, the scale is different — quality 30 in AVIF is roughly equivalent to quality 75 in JPG. Always test on your actual content before committing to a global setting.

FAQ

Should I always use AVIF since it produces the smallest files?
Not necessarily. AVIF encoding is computationally expensive, which can slow down image pipelines significantly. For static sites with a build step, AVIF is great. For real-time uploads (user-generated content), WebP is often a better balance.
Why does my PNG screenshot look fine but the JPG version is blurry?
JPG's compression model is optimized for natural photographs and degrades poorly on text and sharp edges. For screenshots, use PNG or WebP lossless — they preserve the exact pixels and typically produce smaller files than JPG anyway.
Can I convert HEIC photos directly in my browser?
Yes. Our Image Format Converter accepts HEIC input and converts to JPG, PNG, WebP, AVIF, or SVG entirely in your browser — no upload required.
Is there a single best format I should always use?
No. The right format depends on content type (photo vs. graphic), transparency needs, target browsers, and encode time budget. Use the cheat sheet in this guide as a starting point and test on your actual content.

In summary

Match the format to the content: WebP for photos, PNG or SVG for graphics, AVIF when bandwidth matters and encode time does not. For one-off conversions, our Image Format Converter handles JPG, PNG, WebP, AVIF, SVG, and HEIC entirely in your browser, with no uploads.

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