Free · Lossless · Byte-exact
Compress CSV Files Online
Create a .csv.gz download from the original CSV bytes without parsing or normalizing the source.
CSV → Gzip
The original CSV bytes are preserved in the gzip output.
Gzip packages original bytes; it does not trim values or remove duplicate rows. To restore elsewhere: gzip -dk report.csv.gz. For different goals, clean records, split your CSV or convert to Parquet.
- Choose your CSV
Select a non-empty .csv file up to 50 MB, or try the sales sample.
- Compress CSV
Run the operation and check the original and gzip sizes.
- Download gzip
Save the result with the original file bytes preserved.
Byte-exact round trip
What the CSV compressor does
The compressor preserves the selected file as-is. Byte order marks, delimiters, quotes, encodings, and line endings remain part of the original byte sequence and return unchanged after decompression.
Inputs must be non-empty .csv files no larger than 50 MB. The download appends .gz to the complete original filename, such as report.csv.gz.
Plain answers
CSV compression questions
Does compression change my CSV?+
No. The original file bytes are passed directly into gzip without parsing or reserializing the CSV. Decompressing the result restores the exact selected bytes.
Will gzip always make a CSV smaller?+
No. Repeated text usually compresses well, but a very small or high-entropy CSV can grow because a gzip file also contains framing data.
How do I open the .csv.gz download?+
Select Restore gzip on this page to restore the exact original bytes. Compressed inputs and restored outputs are limited to 50 MB. You can also use a gzip-compatible archive tool or command.