Google Web Picture Format (.webp)

RFC 표준

WebP is a modern image format developed by Google that provides superior lossless and lossy compression for web images, supporting both alpha transparency and animated frames.

발명자: Google (based on On2 Technologies VP8 video codec)연도: 2010MIME: image/webp

JPG을(를) WEBP(으)로 변환

무료 브라우저 내 JPG-WEBP 변환기. 기기에서 파일을 즉시 변환하세요.

JPG에서 WEBP로 변환기 →

WebP 온라인 압축

브라우저 내 100% 안전한 압축 — 파일이 기기 외부로 전송되지 않습니다

WebP 압축 →

검사 및 메타데이터

운영 체제와 파일 분석기는 파일 선두의 바이너리 바이트 시퀀스를 검사하여 WebP 파일을 식별합니다:

바이트 단위 헤더 시그니처 (매직 바이트)

운영 체제와 파일 분석기는 파일 선두의 바이너리 바이트 시퀀스를 검사하여 WebP 파일을 식별합니다:

16진수 시그니처 (오프셋 0):

52 49 46 46

ASCII 표현: RIFF

표준화: RFC 6386 / RIFF Container Specification

기술 사양

컨테이너 아키텍처	Resource Interchange File Format (RIFF) container with 'WEBP' FourCC
압축	Lossy VP8 predictive intra-frame coding & Lossless VP8L spatial entropy coding
바이트 엔디안	Little-Endian for RIFF chunk sizes and container tags
색 공간	sRGB, Embedded ICC Profiles (via VP8X extended header)
채널 및 구조	RGB + Alpha (8-bit per channel)
최대 크기	16,383 x 16,383 pixels (14-bit unsigned integers)
투명도	Full 8-bit alpha channel transparency in both lossy and lossless modes
스트리밍 및 프로그레시브	Progressive decoding supported via incremental VP8 block decoding

기술 비교 매트릭스: WebP 대 경쟁사

기술적 속성	WebP (현재)	JPEG	PNG	AVIF
Supported Compression Modes	Both Lossy (VP8) and Lossless (VP8L)	Lossy only	Lossless only	Both Lossy (AV1) and Lossless
Alpha Transparency	Yes (both lossy and lossless)	No	Yes	Yes
Animation Support	Yes (multi-frame with frame delays)	No	Requires APNG extension	Yes (AVIF image sequences)
HDR / Wide Color Gamut	8-bit sRGB only	8-bit standard	8-bit & 16-bit	10-bit & 12-bit native HDR
Browser Support	97%+ global support across all modern browsers	100% universal	100% universal	93%+ modern browsers

일반적인 손상 모드 및 헥스 복구 가이드

⚠️ Browser fails to display WebP image or shows broken image icon.

근본 원인: RIFF payload length header (bytes 4-7) does not match the actual byte length on disk.

복구: Recalculate total file size minus 8 bytes, and patch the 4-byte Little-Endian unsigned integer at offset 0x04.

⚠️ Decoder fails with 'Invalid FourCC: Expected WEBP'.

근본 원인: Bytes 8-11 do not contain the ASCII characters 'WEBP'.

복구: Verify offset 0x08 contains 0x57 0x45 0x42 0x50 ('WEBP') and that the chunk header matches 'VP8 ' or 'VP8L'.

보안 분석 및 파서 공격 벡터

WebP parsing gained intense security scrutiny following CVE-2023-4863, leading to widespread sandbox hardening across all major web browsers.

알려진 공격 벡터

CVE-2023-4863: Heap buffer overflow in libwebp's BuildHuffmanTable function when parsing invalid lossless Huffman tables, allowing remote code execution.
Integer overflow when decoding oversized animation frame canvas dimensions.

방어적 모범 사례: Ensure all client and server libraries use libwebp 1.3.2 or later. Decode WebP files in memory-sandboxed worker threads.

역사적 배경 및 주요 이력

2020Apple Safari 14 adds native WebP support, achieving 100% universal major browser coverage.

2012WebP adds lossless compression (VP8L), alpha channel transparency, and animation.

2010Google releases WebP as an open-source image format to accelerate web performance.

주요 장점

Lossy WebP images are 25%–35% smaller than comparable JPEG images at identical SSIM quality.
Lossless WebP is typically 26% smaller than standard PNG.
Single unified format handles photos, graphics with transparency, and lightweight animated clips.

기술적 제한 사항 및 단점

Maximum dimensions capped at 16,383 x 16,383 pixels, preventing ultra-high resolution panoramic imagery.
Only supports 8-bit color depth (no native 10-bit or 12-bit HDR support).
Encoding complex lossy images requires more CPU cycles than legacy JPEG encoders.

흥미로운 기술적 상식

WebP is based on the keyframe intra-prediction algorithms of Google's open-source VP8 video codec.
The RIFF container used by WebP is the exact same container architecture used by classic Microsoft AVI and WAV files.
Animated WebP files are typically 60%–80% smaller than animated GIFs.

자주 묻는 기술 질문

Can WebP completely replace both PNG and JPEG?

Yes. For web use, WebP provides superior compression for both photographic content (replacing JPEG) and transparent graphics (replacing PNG). Its universal browser support makes it a primary format for modern web optimization.

Why is WebP lossless compression more efficient than PNG?

WebP lossless uses advanced spatial predictors, color transform decorrelation, a localized color cache, and entropy-coded 2D transforms, resulting in files that are typically 26% smaller than optimal PNGs.

Does WebP support animation?

Yes. WebP supports multi-frame animation with variable frame delays, full alpha transparency per frame, and disposal methods, delivering 60%–80% smaller payloads than traditional animated GIFs.