Archive
A category of file formats covered by Format Atlas.
About this category
BrotliBrotli (.br) is a lossless compressed data format using LZ77-family references and Huffman coding. It is also used as the HTTP content-coding token br; servers may deliver precompressed files when the client supports it. The stream is not an archive and does not necessarily include metadata such as the original size or a checksum.BZIP2BZIP2 compresses data losslessly. A .bz2 file usually compresses one data stream; tar.bz2 combines tar archiving with BZIP2 compression.GZIPGZIP compresses data losslessly. A .gz file commonly wraps one file; tar.gz first groups files with tar and then compresses that archive.ISO ImageAn ISO image stores optical-media contents and structure in one file. It differs from a compressed archive.LZ4A .lz4 file usually stores one losslessly compressed data stream in the LZ4 frame format. This article covers official frame specification 1.6.4, not raw blocks or legacy frames.RARRAR is an archive format associated with RARLAB. Creating and extracting archives may depend on different tools and licensing terms; support is not universal.7Z7Z is an archive format used by 7-Zip and compatible tools. Compression and optional encryption settings can vary, so recipients need an extractor that supports the chosen options.TARTAR bundles files, directories, and metadata into one archive. TAR alone does not compress them; tar.gz, tar.bz2, and tar.xz add separate compression layers.XZXZ is a container for compressed data streams, often used with lossless LZMA2 compression. It does not itself archive multiple files; tar.xz compresses a tar archive.ZIPZIP packages files and folders into an archive. Compression methods and optional encryption depend on how the archive was created and what the receiving tool supports.ZstandardZstandard (zstd, .zst) is a lossless compression format. It offers selectable compression levels, frame-based sequential processing, and optional dictionaries for suitable workloads. Speed and compression ratio depend on data, settings, and implementation. A .zst stream does not itself archive multiple files.