Best Image Size and Format for Bitcoin Ordinal Inscriptions
Every byte you inscribe on Bitcoin costs real money. The difference between a 5KB and a 500KB file can mean hundreds of dollars in inscription fees. This guide covers the exact image dimensions, file formats, and optimization techniques that will get your art on-chain without breaking the bank.
Recommended Image Dimensions
There is no single "correct" size for Ordinal inscriptions, but practical sweet spots exist based on how inscriptions are displayed across explorers, wallets, and marketplaces.
- 400x400 pixels — Minimum recommended for most art. Displays sharply on all devices and keeps file size manageable.
- 512x512 pixels — The most common size for PFP collections. Balances quality and cost effectively.
- 1000x1000 pixels — Upper practical limit for raster images. Larger than this and inscription fees climb fast with minimal visual benefit, since most viewers cap display size.
- 24x24 to 100x100 pixels — Ideal for pixel art. Let the browser scale up. A 24x24 pixel art piece looks identical to a 2400x2400 upscale, but costs a fraction to inscribe.
File Formats Ranked by Efficiency
Not all formats are equal on Bitcoin. Here is how they stack up for Ordinal inscriptions, ranked from most efficient to least:
| Format | Best For | Typical Size | Notes |
|---|---|---|---|
| SVG | Vector art, generative art | 500B – 10KB | Smallest possible. Resolution-independent. Can include animations via CSS/JS. |
| WebP | Photos, complex art | 5KB – 80KB | 30-50% smaller than PNG at same quality. Growing support across explorers. |
| PNG | Pixel art, illustrations | 500B – 200KB | Most universally compatible. Supports transparency. Highly optimizable. |
| GIF | Simple animations | 10KB – 400KB | Each frame adds size. Keep under 10 frames for affordability. |
| JPEG | Photography | 10KB – 150KB | Lossy compression. Good for photos but introduces artifacts in flat art. |
SVG: The Smallest Option
SVG inscriptions are vector-based, meaning they scale to any resolution with zero quality loss. A complex SVG artwork can weigh just 2-5KB. Generative art projects love SVG because the code itself is the art — and code compresses extremely well.
Use SVGO (SVG Optimizer) to strip metadata, unnecessary attributes, and whitespace. A typical SVGO pass reduces SVG size by 20-50%.
WebP: Best Compression for Raster Art
WebP offers superior compression compared to PNG and JPEG. A 512x512 illustration that weighs 80KB as PNG might be just 35KB as WebP. The tradeoff is slightly less universal support, though all major Ordinals explorers now render WebP correctly.
PNG: Most Compatible
PNG remains the default choice for most inscriptions. It is lossless, supports transparency, and is rendered everywhere. The key is optimization — an unoptimized PNG can be 5-10x larger than necessary.
GIF: Handle With Care
Animated GIFs are popular for Ordinals art, but file sizes add up fast. Each frame is essentially a separate image. A 10-frame animation at 400x400 can easily exceed 200KB. Keep animations to 3-8 frames and use small canvas sizes to stay affordable.
Size Optimization Techniques
Every artist inscribing on Bitcoin should know these optimization tools and techniques:
PNG Optimization
- PNGCrush / OptiPNG — Lossless compression that strips unnecessary chunks and finds optimal encoding. Typically saves 10-30%.
- TinyPNG (tinypng.com) — Lossy PNG compression using quantization. Can reduce file size by 60-80% with minimal visible quality loss.
- pngquant — Command-line tool for reducing color palette. Converting from 24-bit to 8-bit (256 colors) can cut file size by 60-80%.
Color Palette Reduction
This is the single most effective technique for reducing PNG file size. Most digital art does not need millions of colors:
- 16 colors — Sufficient for most pixel art. Can reduce PNG size by 70-80%.
- 32-64 colors — Good for illustrations with gradients. Saves 50-70%.
- 256 colors (8-bit) — Works for complex art. Saves 40-60% vs. 24-bit.
SVG Optimization
- SVGO — The standard SVG optimizer. Run with default presets for 20-50% reduction.
- Remove metadata — Strip editor data, comments, and unused definitions.
- Simplify paths — Reduce decimal precision in path coordinates. Rounding to 1-2 decimals saves bytes with negligible visual change.
Target File Sizes for Inscription Fees
Inscription fees scale linearly with file size. Here are practical targets:
| File Size | Fee Estimate (20 sat/vB) | Use Case |
|---|---|---|
| Under 1KB | ~$0.50 – $2 | Tiny pixel art, text, minimal SVG |
| Under 10KB | ~$2 – $8 | Pixel art, optimized SVG, small PNG |
| Under 50KB | ~$8 – $30 | Sweet spot for most art. Good quality at reasonable cost. |
| Under 100KB | ~$30 – $60 | Detailed illustrations, photos |
| Under 400KB | ~$60 – $250 | Maximum practical limit. Reserve for premium 1/1 pieces. |
Pixel Art: The Most Efficient Ordinal Art
Pixel art is uniquely suited to Bitcoin inscriptions because of its tiny file sizes:
- 24x24 at 4 colors — Typically 200-500 bytes. Nearly free to inscribe.
- 32x32 at 8-bit color — Typically 500 bytes to 2KB.
- 100x100 at 8-bit color — Typically 5-10KB.
- 100x100 at 24-bit color — Typically 15-30KB.
This makes pixel art the most cost-effective style for large collections (1K-10K pieces) where inscription costs multiply across every item.
Quick Checklist Before Inscribing
- Choose the smallest canvas size that preserves your art's intent
- Pick the right format: SVG for vectors, PNG for pixel art, WebP for complex raster
- Reduce color palette if possible (16-64 colors for most art)
- Run through an optimizer (SVGO, TinyPNG, pngquant, OptiPNG)
- Target under 50KB for affordable inscriptions
- Check current fee rates on mempool.space
- Never upscale pixel art — inscribe at native resolution
See Optimized Ordinals Art in Action
Browse inscriptions from artists who have mastered file optimization
Visit ordinals.pics Gallery