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What Is PNG Format? When to Use It and When to Switch

By Picovert Team2026-05-255 min read

PNG (Portable Network Graphics) is a lossless image format that preserves every pixel exactly as captured. It supports transparent backgrounds, making it the go-to format for logos, icons, and UI elements. The tradeoff: PNG files are much larger than JPEG for photos, and larger than WebP for everything. This guide explains what PNG is, when to use it, and when to switch to a smaller format.

What PNG Means

PNG was created in 1995 as a patent-free replacement for GIF. The name stands for Portable Network Graphics. Key characteristics:

  • Lossless compression: compresses image data without discarding any information. Every pixel value is preserved exactly. Opening, saving, and re-saving a PNG never reduces quality
  • Transparency (alpha channel): PNG supports full 8-bit alpha channel — each pixel can be fully transparent, fully opaque, or any opacity in between. This is PNG's biggest advantage over JPEG
  • RGB color: supports 24-bit RGB (16.7 million colors) and 32-bit RGBA (RGB + alpha). Also supports 8-bit indexed color (PNG-8, up to 256 colors)
  • Lossless = large files: PNG stores all pixel data, which means photo files are 5–20× larger than the equivalent JPEG at 85% quality

PNG vs JPEG vs WebP — When to Use Each

  • PNG: logos, icons, screenshots, UI mockups, graphics with text, any image needing transparency. Use when lossless quality is required or transparency is needed
  • JPEG: photographs and complex images without transparency. 5–10× smaller than PNG for photos. No support for transparency
  • WebP: best for web — 25–35% smaller than JPEG for photos, supports transparency like PNG but at much smaller sizes. Supported in all modern browsers. Convert PNG to WebP with our PNG to WebP converter
  • AVIF: even smaller than WebP (30–50% smaller than JPEG), supports transparency. Best choice for web images in 2025+.Convert PNG to AVIF

File Size Comparison

For a typical 1920×1080 photo:

  • PNG: 2–6 MB (lossless)
  • JPEG at 85% quality: 200–500 KB (4–15× smaller)
  • WebP at 80% quality: 150–350 KB (6–20× smaller)
  • AVIF at 80% quality: 80–200 KB (10–40× smaller)

For a 512×512 logo/icon with transparency:

  • PNG: 20–150 KB (lossless, transparency preserved)
  • WebP: 10–80 KB (smaller, transparency preserved)
  • JPEG: not usable — doesn't support transparency

PNG-8, PNG-24, and PNG-32 Explained

  • PNG-8: 8-bit indexed color — up to 256 colors, supports binary transparency (fully transparent or fully opaque). Good for simple icons and web graphics. Very small files
  • PNG-24: 24-bit RGB — 16.7 million colors, no transparency. Larger than PNG-8 but full color fidelity for photos and complex graphics
  • PNG-32: 32-bit RGBA — 16.7 million colors + full alpha transparency. The most common PNG type for logos and UI assets that need smooth transparent edges (anti-aliased transparency)

How PNG Compression Works

PNG uses a two-step lossless compression process:

  1. Filtering: each row of pixels is processed with one of five filters (None, Sub, Up, Average, Paeth) that predict pixel values based on neighbors. This makes patterns more compressible
  2. Deflate compression: the filtered data is compressed using the deflate algorithm (same as ZIP and gzip). This finds repeated patterns and replaces them with shorter references

Because it's lossless, PNG compression saves space by finding repeated patterns — it can't reduce file size by reducing quality. A photo with millions of slightly-different pixel colors compresses poorly in PNG. A simple graphic with large solid-color areas compresses very well.

When to Convert PNG to Another Format

  • For web performance: convert PNG photos to WebP or AVIF to reduce load time. PNG to WebP typically reduces photo size by 70–85% with negligible visual difference
  • For logos on web: convert PNG logos to WebP — you keep the transparency but at 50–70% smaller file size
  • For email attachments: convert PNG photos to JPEG for email — smaller files that most recipients can open regardless of their email client
  • For print: keep PNG or convert to TIFF — both are lossless and preserve full quality for printing

Compressing PNG Files

You can reduce PNG file size without converting to a lossy format using lossless PNG optimization (pngcrush, oxipng). This re-compresses the PNG more efficiently without changing any pixel values — typically 10–30% smaller than a default-saved PNG.

For bigger savings, use the image compressor which converts to a more efficient format. Or use lossy PNG compression (pngquant) which reduces PNG-32 to PNG-8 — effective for simple graphics but can show color banding in complex gradients.