Batch file renamer
Rename multiple files with a live filename preview, prefixes, numbering and a ZIP download of the original contents.
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Files & archives
Inspect, compare, hash, and package files on your device.
Binary hex viewer
Browse any file as hexadecimal bytes and ASCII with precise offsets, paged navigation and page export.
File compare
Compare two files byte for byte with an interactive difference map, exact counts and a downloadable report.
GZIP compressor
Compress a file locally with fast, balanced or smallest GZIP settings and compare the resulting file size.
GZIP decompressor
Restore a single-member GZIP file locally with header, size and CRC-32 integrity checks.
ZIP creator
Package files into one ZIP with portable filenames. Reorder the list and download original bytes in a stored archive.
ZIP extractor
Browse ZIP entries, choose files and extract verified contents locally with bounded expansion and CRC checks.
ZIP inspector
Explore ZIP filenames, declared sizes and compression methods in an interactive directory without extracting contents.
Browse the bytes of any file, diff two files precisely, calculate checksums, compress and decompress GZIP, inspect ZIP archives, and build archives with portable names.
Files are read locally, expansion is bounded, and archive metadata is clearly separated from verified contents.
Archives, compression, and inspection
The ZIP creator packages files into one archive with names that work on every operating system. The ZIP inspector lists what an archive contains without extracting anything, and the ZIP extractor pulls out selected files and verifies each one's checksum. For single files, the GZIP tools compress and decompress with integrity checks. The batch file renamer applies prefixes, numbering, and find-and-replace to many file names at once and returns the renamed copies as a ZIP.
For looking inside files, the binary hex viewer shows raw bytes with offsets, which is the fastest way to identify a file's real type from its signature. File compare finds exactly where two files differ, byte by byte.
Safe handling of untrusted files
Archives from unknown sources can be hostile. Zip bombs expand from kilobytes to gigabytes, and path-traversal entries try to write outside the extraction folder. The archive tools limit expansion, reject unsafe entry names, and never execute contents. Inspecting an attachment first and extracting only what you need is a sensible habit for any download.
Files are read into your browser's memory and processed there, with limits of 16 MiB per file and 32 MiB in total so the page stays responsive. Nothing is uploaded, which matters for backups, exports, and documents that contain personal data.