Decision guide
Best image format for transparency
Transparent artwork needs a real alpha channel, not a single transparent colour index. The engine ranks image formats on alpha support first, then on delivery cost.
Short answer: AVIF ranks first (85/100) because it supports transparency.
The ranking, and the reasoning behind it
Scores are computed from structured facts in the knowledge graph, weighted for this specific question. Nothing here is written by hand, and every line of reasoning traces back to a recorded fact.
#1AVIF
85/100
AVIF is an AV1-based image format with the strongest compression of the web formats.
Why it scores well
- Transparency 100/100 — it supports transparency; it stores a full alpha channel, allowing soft edges and partial opacity.
- Browser compatibility 100/100 — every major browser engine renders it natively; at least one shipping browser renders it.
- Compression efficiency 100/100 — it compresses lossily, which produces much smaller files than lossless coding; it uses a recent codec generation, which encodes more efficiently than older designs.
All AVIF factsWhere it loses points
- Image quality 33/100 — it discards detail during encoding, and every re-save compounds the loss.
#2PNG
83/100
PNG is a lossless raster format with full alpha transparency, built for graphics.
Why it scores well
- Transparency 100/100 — it supports transparency; it stores a full alpha channel, allowing soft edges and partial opacity.
- Browser compatibility 100/100 — every major browser engine renders it natively; at least one shipping browser renders it.
- Image quality 100/100 — it is lossless, so decoding returns the original pixels exactly; it carries ICC colour profiles, so colours survive the round trip.
All PNG factsWhere it loses points
- Compression efficiency 23/100 — it stores data losslessly, so files stay large; its codec generation predates modern entropy coding and block partitioning.
#3ICO
78/100
ICO is the Windows icon container holding several sizes in one file.
Why it scores well
- Transparency 100/100 — it supports transparency; it stores a full alpha channel, allowing soft edges and partial opacity.
- Browser compatibility 100/100 — every major browser engine renders it natively; at least one shipping browser renders it.
- Image quality 100/100 — it is lossless, so decoding returns the original pixels exactly.
All ICO factsWhere it loses points
- Compression efficiency 0/100 — it stores data losslessly, so files stay large.
#4SVG
78/100
SVG is an XML vector format that stays sharp at any size.
Why it scores well
- Transparency 100/100 — it supports transparency.
- Browser compatibility 100/100 — every major browser engine renders it natively; at least one shipping browser renders it.
- Image quality 100/100 — it is lossless, so decoding returns the original pixels exactly.
All SVG factsWhere it loses points
- Compression efficiency 0/100 — it stores data losslessly, so files stay large; its codec generation predates modern entropy coding and block partitioning.
#5WebP
78/100
WebP is Google's web image format offering lossy and lossless modes with alpha.
Why it scores well
- Transparency 100/100 — it supports transparency; it stores a full alpha channel, allowing soft edges and partial opacity.
- Browser compatibility 100/100 — every major browser engine renders it natively; at least one shipping browser renders it.
- Compression efficiency 69/100 — it compresses lossily, which produces much smaller files than lossless coding; it defines a documented compression scheme.
All WebP factsWhere it loses points
- Image quality 33/100 — it discards detail during encoding, and every re-save compounds the loss.
#6BMP
74/100
BMP is an uncompressed Windows raster format that trades size for simplicity.
Why it scores well
- Browser compatibility 100/100 — every major browser engine renders it natively; at least one shipping browser renders it.
- Image quality 100/100 — it is lossless, so decoding returns the original pixels exactly.
All BMP factsWhere it loses points
- Compression efficiency 23/100 — it stores data losslessly, so files stay large; its codec generation predates modern entropy coding and block partitioning.
#7GIF
70/100
GIF is a 256-colour raster format best known for short looping animations.
Why it scores well
- Browser compatibility 100/100 — every major browser engine renders it natively; at least one shipping browser renders it.
- Image quality 100/100 — it is lossless, so decoding returns the original pixels exactly.
- Transparency 60/100 — it supports transparency.
All GIF factsWhere it loses points
- Compression efficiency 23/100 — it stores data losslessly, so files stay large; its codec generation predates modern entropy coding and block partitioning.
#8TIFF
68/100
TIFF is a flexible lossless raster format used in print, scanning and archiving.
Why it scores well
- Transparency 100/100 — it supports transparency; it stores a full alpha channel, allowing soft edges and partial opacity.
- Image quality 100/100 — it is lossless, so decoding returns the original pixels exactly; it carries ICC colour profiles, so colours survive the round trip.
All TIFF factsWhere it loses points
- Compression efficiency 23/100 — it stores data losslessly, so files stay large; its codec generation predates modern entropy coding and block partitioning.
- Browser compatibility 33/100 — native browser support is incomplete or undocumented.
How this ranking is calculated
Each format is scored 0–100 on every dimension the graph can evaluate for it. For this question the dimensions carry these weights:
- transparency ×3
- browser compatibility ×2
- compression efficiency ×2
- image quality ×2
No machine learning is involved. The engine is deterministic: the same facts always produce the same ranking, and adding a new fact to the graph updates it automatically.