file in abyss

3D

Avocado GLB

GLB

7.73 MB

Aud

Lake Waves MP3 8s

MP3

Vid

Cloud Flight MP4 8s

MP4

1080 x 1920

Img

Blue Night Sky JPG

JPEG

960 x 640

Img

Sun Beauty WebP

WEBP

4160 x 3120

Data

Arctic Sky JSON

JSON

1.1 KB

Img

NASA Earth 2048x2048 PNG

PNG

2048 x 2048

In-browser analysis

Files are not uploaded. The browser reads only the first few kilobytes locally.

Choose a file

Why use it

File detection and sample testing in one place

Extensions and MIME types are not always enough. file in abyss combines signatures, structures, caveats, detection snippets, and downloadable test samples on each format page.

Analyze locally

The selected file stays in the browser while its leading bytes are checked locally.

Samples included

Use small files, large files, different resolutions, and varied durations to test real implementations.

Caveats included

Each page calls out false positives, security concerns, and container-format edge cases.

Format directory

Find a format

PNG Portable Network Graphics

Lossless raster image format. A fixed 8-byte signature is immediately followed by the IHDR chunk.

.png image/png

PDF Portable Document Format

Page-oriented document format. The version declaration usually starts at %PDF- near the beginning of the file.

.pdf application/pdf

ZIP ZIP Archive

Archive format that stores multiple files. It is also the container for many formats such as DOCX, XLSX, APK, JAR, and EPUB.

.zip application/zip

GZ GZIP Compressed Data

Single-stream compression format. The leading 1F 8B is followed by the compression method, usually 08 (deflate).

.gz application/gzip

TAR Tape Archive

Archive format that concatenates multiple files. It is built from 512-byte headers and data blocks.

.tar application/x-tar

GIF Graphics Interchange Format

Format used for indexed-color images and simple animation. It has two header variants, GIF87a and GIF89a.

.gif image/gif

JPG JPEG File Interchange Format

Lossy compressed image format for photos. It starts with the SOI marker FF D8.

.jpg image/jpeg

WEBP WebP Image

Web image format developed by Google. It carries a WEBP form type inside a RIFF container.

.webp image/webp

AVIF AV1 Image File Format

Image format that stores AV1-compressed images in an ISO BMFF container. Used for highly compressed web images.

.avif image/avif

BMP Windows Bitmap

Long-standing raster image format on Windows. The leading BM is followed by a DIB header.

.bmp image/bmp

TIF Tagged Image File Format

Image format used for photography, printing, and scanning. The start indicates endianness and a 42 marker.

.tif image/tiff

SVG Scalable Vector Graphics

XML-based vector image format. It is human-readable text and can be displayed directly in browsers.

.svg image/svg+xml

WAV Waveform Audio File Format

RIFF-based audio format widely used for uncompressed PCM audio. Identified by leading RIFF and WAVE at byte 8.

.wav audio/wav

MP3 MPEG Audio Layer III

Lossy audio format widely used for music distribution and web playback. It starts with an ID3 tag or an MPEG frame sync.

.mp3 audio/mpeg

FLAC Free Lossless Audio Codec

Lossless audio format. The leading fLaC marker is followed by metadata blocks.

.flac audio/flac

OGG Ogg Container

Container format that can hold Vorbis, Opus, and more. Each page starts with the OggS capture pattern.

.ogg audio/ogg

M4A MPEG-4 Audio

Format that stores audio such as AAC in an ISO BMFF / MPEG-4 container. It normally has an ftyp box.

.m4a audio/mp4

AAC Advanced Audio Coding

Raw AAC streams may use the ADTS header. The start is typically FF F1 or FF F9.

.aac audio/aac

Video

MP4 MPEG-4 Part 14

ISO BMFF-based container format widely used for web video. The ftyp box type usually appears from byte 4.

.mp4 video/mp4

Video

WEBM WebM

Web-oriented Matroska-derived container. It starts with the EBML header 1A 45 DF A3.

.webm video/webm

Video

AVI Audio Video Interleave

Long-standing RIFF-based video container. Identified by leading RIFF and AVI at byte 8.

.avi video/x-msvideo

PLY Polygon File Format

A 3D geometry format, also called the Stanford Triangle Format. It starts with an ASCII ply header; for Gaussian Splatting it stores per-point properties such as color, opacity, scale, and rotation.

.ply model/ply

GLTF glTF JSON

Runtime-oriented format that describes 3D scenes in JSON, holding asset info, scenes, nodes, meshes, and materials.

.gltf model/gltf+json

GLB Binary glTF

Format that packs glTF JSON and binary data into a single file. The first 4 bytes are glTF.

.glb model/gltf-binary

VRM VRM Avatar

Format that builds on glTF/GLB with metadata and extensions for humanoid avatars. The file starts with glTF, just like GLB.

.vrm model/vrm

JSON JavaScript Object Notation

Text-based data format widely used by web APIs and config files. It usually starts with an object or an array.

.json application/json

XML Extensible Markup Language

Text format that expresses structure with tags and attributes. It starts with an XML declaration or a root element.

.xml application/xml

CSV Comma-Separated Values

Text format that represents tabular data with comma separators. It often has a header row.

.csv text/csv

.docx application/vnd.openxmlformats-officedocument.wordprocessingml.document

DOCX Word Open XML Document

Office Open XML document widely used by Microsoft Word. It is actually a ZIP package containing files such as word/document.xml.

.xlsx application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

XLSX Excel Open XML Workbook

Office Open XML workbook widely used by Microsoft Excel. It is actually a ZIP containing xl/workbook.xml and worksheet XML.

.pptx application/vnd.openxmlformats-officedocument.presentationml.presentation

PPTX PowerPoint Open XML Presentation

Office Open XML presentation widely used by Microsoft PowerPoint. It is actually a ZIP containing ppt/presentation.xml and slide XML.

.odt application/vnd.oasis.opendocument.text

ODT OpenDocument Text

OpenDocument text format used by LibreOffice and OpenOffice. Its ZIP container holds mimetype and content.xml.

EPUB Electronic Publication

EPUB format widely used for e-books. It is a ZIP container holding mimetype, container.xml, the OPF, and XHTML content.

.epub application/epub+zip

YAML YAML Ain’t Markup Language

Human-readable text format widely used for config files and data description. It has no fixed binary signature.

.yaml application/yaml

MD Markdown

Lightweight markup widely used for READMEs and technical docs. It has no fixed binary signature.

.md text/markdown

Web

HTML HyperText Markup Language

Standard markup format for web pages. Many HTML documents start with <!doctype html> or <html>.

.html text/html

Web

CSS Cascading Style Sheets

Stylesheet that defines the appearance of web pages. It has no fixed binary signature.

.css text/css

Code

JS JavaScript

Source file for a programming language widely used on the web and in Node.js. It has no fixed binary signature.

.js text/javascript

RTF Rich Text Format

Rich text document format. It opens in many editors including Word and usually starts with {\rtf.

.rtf application/rtf

TXT Plain Text

The most general plain-text format. It has no fixed binary signature.

.txt text/plain

TSV Tab-Separated Values

Text format that represents tabular data with tab separators. It handles commas within fields better than CSV.

.tsv text/tab-separated-values

NDJSON Newline Delimited JSON

Streaming-oriented data format that places one JSON value per line. Common in logs and batch processing.

.ndjson application/x-ndjson

TOML Tom's Obvious Minimal Language

Text format used for config files. It expresses keys, tables, and arrays in a human-readable way.

.toml application/toml

.webmanifest application/manifest+json

INI INI Configuration

Text format of sections and key-values widely used for config files, on Windows and in many tools.

.ini text/plain

Web

WEBMANIFEST Web App Manifest

JSON-based web app config file that describes a PWA's name, icons, and display mode.