Image MIME Reference

Share Copy URL

BPG

Better Portable Graphics MIME Type Reference

image/bpg Released 2014 · by Fabrice Bellard

Better Portable Graphics (BPG) is a modern, high-efficiency raster image format created in 2014 by programmer Fabrice Bellard. It wraps the intra-frame encoding of the HEVC (H.265) video compression standard, offering phenomenal compression ratios, native alpha channel transparency, and high color depths.

Professional & Broadcast Imaging Transparency Animation Production Ready

Copy Link Twitter LinkedIn

Technical Specifications

MIME Type

image/bpg

Extensions

.bpg

Container

Custom BPG Header

Compression

HEVC (H.265) Intra-frame & Lossless

Algorithms

HEVC (H.265)

Color Depth

8-bit (Per Channel), 10-bit (Per Channel), 12-bit (Per Channel), 14-bit (Per Channel)

Metadata

EXIF XMP ICC

Capabilities

Transparency

Animation

Progressive Loading

Alpha Channel

HDR Support

Official Specification

Aliases: image/x-bpg

Magic Bytes & HTTP Headers

File Signature (Magic Bytes)

Copy

42 50 47 FB

ASCII: BPG\xFB

HTTP Headers

Content-Type: image/bpg

HTML Accept Attribute

accept="image/bpg, .bpg"

Browser Support Matrix

Browser	Status	Min Version
Chrome	Not Supported	—
Firefox	Not Supported	—
Safari	Not Supported	—
Edge	Not Supported	—
Internet Explorer	Not Supported	Legacy

Advantages & Limitations

Advantages

• Exceptional compression efficiency that vastly outperforms standard JPEG at similar quality levels
• Supports high bit depths (up to 14 bits per channel), lossless compression, and alpha channel transparency within a single format
• The official JavaScript decoder allows the format to be rendered on standard HTML5 canvas elements

Limitations

• HEVC (H.265) patent encumbrance prevented native adoption in major web browsers
• Superseded conceptually by the open, royalty-free AVIF format
• Encoding BPG files is computationally intensive and requires specialized command-line tools

Developer Code Snippets

Python Node.js Go PHP

Copy

import magic
print(magic.from_file('file.bpg', mime=True)) # Outputs 'image/bpg'

const FileType = require('file-type');
const type = await FileType.fromFile('file.bpg');
console.log(type.mime); // image/bpg

import "net/http"

mimeType := http.DetectContentType(fileBytes)
fmt.Println(mimeType) // Note: Standard net/http may default to application/octet-stream for BPG

$mime = mime_content_type('file.bpg');
echo $mime; // image/bpg

File Detection Steps

How to programmatically detect a image/bpg file by reading its raw bytes:

1. 1 Check the first 4 bytes for the BPG signature (42 50 47 FB)
2. 2 Include the official 'bpgdec.js' Javascript decoder library if serving via web, as standard HTML <img> tags will fail

Software Support

b

bpgview (Official Viewer)

I

ImageMagick

X

XnView

H

Honeyview

Free Online Tools for BPG

Free Image Resizer

Editor

Resize, scale, crop, and modify dimensions for any photo or graphic.

Open Tool

Image Metadata Remover

Privacy

Clean EXIF, camera, lens, and location tags from your photos.

Open Tool

WebP to JPG Converter

Universal

Convert modern web images to universal high-compatibility JPG.

Open Tool

Compress WebP Images

Optimizer

Reduce image file sizes for faster web performance.

Open Tool

BPG Format Comparisons

BPG vs HEIC AVIF vs BPG BPG vs WebP BPG vs JPEG BPG vs FLIF BPG vs PNG BPG vs GIF BPG vs SVG BPG vs TIFF BMP vs BPG BPG vs JXL

View all format comparisons

Share & Embed

Markdown Badge

[![BPG Format](https://freewebptojpg.com/mime/image/bpg/badge.svg)](https://freewebptojpg.com/mime/image/bpg)

Interactive iframe Widget

<iframe src="https://freewebptojpg.com/mime/image/bpg/embed" width="100%" height="280" style="border:1px solid #cbd5e1;border-radius:8px;" title="BPG Specs"></iframe>

JSON API

All data on this page is available as a free, open JSON API. Use it in your project, documentation, or tooling.

GET https://freewebptojpg.com/mime/image/bpg.json Copy URL Open JSON

Free to use

No auth required

CORS enabled

Use from any domain

Cached 24h

Cache-Control headers set

Frequently Asked Questions

What is the magic byte for image/bpg?

BPG images contain a 4-byte magic signature at offset 0. The first four bytes are 42 50 47 FB in hex, corresponding to the ASCII string 'BPG' followed by the 0xFB byte.

Is image/bpg natively supported in web browsers?

No. Despite its technical advantages, BPG was never natively adopted by major web browsers due to the patent royalties associated with its underlying HEVC (H.265) compression. It requires a JavaScript polyfill to render on the web.

What is the difference between BPG and AVIF?

Both are next-generation image formats based on video codecs. BPG uses the proprietary HEVC (H.265) codec, while AVIF uses the open, royalty-free AV1 codec. AVIF eventually won the web standard war due to its open licensing model.

Related Formats

HEIC AVIF WebP JPEG FLIF