Free online file tools
Ten instant file utilities that run entirely in your browser. Inspect, convert, and analyse files — no signup, no upload to any server.
-
File Size Converter
Convert file sizes between bytes, KB, MB, GB, and TB instantly with a full unit breakdown.
Open tool →
-
MIME Type Lookup
Look up the MIME type for any file extension, or reverse-lookup extensions for a given MIME type.
Open tool →
-
File Hash Compare
Compute SHA-256 hashes for two files and instantly verify whether they are identical.
Open tool →
-
ZIP Content List
List all files and folders inside a ZIP archive without extracting it — shows names, sizes, and paths.
Open tool →
-
Batch Rename Preview
Preview batch file renames using find-and-replace patterns, prefix/suffix, or sequential numbering.
Open tool →
-
File Extension List
Searchable reference of 150+ file extensions with associated MIME types, categories, and typical programs.
Open tool →
-
Binary Viewer
View the raw binary (0s and 1s) representation of any file — inspect magic bytes and byte patterns.
Open tool →
-
Hex Viewer
Hex dump any file in classic xxd-style output with offset, hex bytes, and ASCII columns.
Open tool →
-
CSV to JSON
Convert CSV data to JSON array or object format — paste or upload, download the result.
Open tool →
-
CSV Validator
Validate CSV structure, detect missing fields, inconsistent columns, and quoting errors.
Open tool →
Why use browser-based file tools?
Every tool here runs entirely inside your browser — no server round trips, no account needed, no data sent to a third party. Whether you are inspecting a ZIP archive, converting file sizes, or validating CSV data, all processing happens locally and results are instant.
Choosing the right tool
Use the File Size Converter when you need to translate bytes to KB, MB, GB, or TB. Use the MIME Type Lookup to find the correct content-type header for any extension. To verify a downloaded file hasn't been tampered with, the File Hash Compare computes SHA-256 checksums in your browser. For data work, the CSV to JSON and CSV Validator tools cover the most common data-pipeline problems.