Fix garbled CSV files
Detect a CSV’s encoding and convert it to UTF-8 (with BOM) or Shift_JIS.
1. Choose a CSV file
Pick a garbled CSV, or a CSV or TSV whose encoding you want to change.
Drag and drop a CSV file here
or
2. Check the encoding
The file was read using the detected encoding. If the table looks garbled, try another encoding.
3. Convert and save
Choose based on the app that will open the file, or the system you’re importing it into.
Save as
Opens in Excel without garbling, even with a double-click. Pick this if you’re not sure.
Everything happens on this device. Your file is never uploaded.
Leading zeros disappearing, dates showing as “####” or numbers turning into “1.2E+10” in Excel aren’t garbled text — they’re how Excel displays the data.
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How to use
1. Choose a CSV file
Tap “Choose files” and pick the garbled CSV file, for example from the Files app.
Drag and drop the garbled CSV file anywhere on the page, or use “Choose files”.
2. Check the contents in the table
The encoding is detected automatically and the contents are shown as a table. You can swipe the table sideways. If it looks garbled, choose another encoding under “Read as” below the table.
The encoding is detected automatically and the contents are shown as a table. If the table looks garbled, choose another encoding under “Read as” in the panel on the right.
3. Choose the encoding to save as
Under “Save as”, choose “UTF-8 BOM” to open the file in Excel, or “Shift_JIS” to import it into an older system. If some characters don’t exist in Shift_JIS, they’re listed along with their line.
Under “Save as” in the panel on the right, choose “UTF-8 BOM” to open the file in Excel, or “Shift_JIS” to import it into an older system. If some characters don’t exist in Shift_JIS, they’re listed along with their line.
4. Save the CSV
Tap “Save CSV” to save the CSV file converted to the encoding you chose.
Press “Save CSV” to save the CSV file converted to the encoding you chose. The encoding is added to the end of the file name (such as _utf8bom).
Great for
A downloaded CSV is garbled in Excel
Convert UTF-8 CSV files exported from online stores, banks or web services to UTF-8 with BOM, so Excel opens them correctly.
Accounting, admin and e-commerce staff
Importing into a system that only takes Shift_JIS
For accounting software or business systems that require a Shift_JIS CSV. Any characters that can’t be written are flagged before you save.
People using Japanese accounting or business software
A CSV from Japanese Windows won’t display on a Mac or phone
Convert Shift_JIS CSV files made on Windows to UTF-8, so they read correctly in Numbers on a Mac or in Google Sheets.
People working on a Mac or iPhone
Finding out a CSV’s encoding
Just choose a file to detect its encoding and line endings and view its contents as a table. No Excel needed.
Engineers exchanging data files
Good to know before you start
- Characters that were already saved as “?” or “�” can’t be recovered. Choose the original file from before it got garbled.
- Only the encoding and line endings change. Delimiters and cell contents stay the same.
- Changing the encoding won’t stop Excel from dropping leading zeros or showing numbers in scientific notation. In Excel, use “Data” → “From Text/CSV” and import those columns as text.
About garbled CSVs and encodings
A CSV gets garbled when it’s read with a different encoding from the one it was written in. With Japanese CSV files, it’s almost always a mix-up between Shift_JIS, long used on Windows in Japan, and UTF-8, the standard on today’s web and phones. Excel reads a UTF-8 CSV without a “BOM” marker at the start in the old local encoding (Shift_JIS on Japanese Windows), so the text comes out garbled.
This tool detects the encoding from the file’s byte patterns and shows the contents as a table. Shift_JIS is handled in its Windows form (CP932), so characters like ①, ㈱ and 髙 are read and written correctly. When converting from UTF-8 to Shift_JIS, any characters that can’t be written (such as emoji) are listed before you save.
FAQ
Answers to common questions about garbled CSV files.
Is my file sent anywhere?
No. Reading, detecting and converting all happen inside the browser on your device, and your file is never uploaded to a server. It’s safe to use with customer lists or sales data.
Why is my UTF-8 CSV garbled when I open it in Excel?
Excel reads a CSV without a BOM at the start in the old local encoding (Shift_JIS on Japanese Windows). Save it again as “UTF-8 BOM” and it will open correctly, even with a double-click.
What is a BOM?
A 3-byte marker (EF BB BF) at the start of a file that tells apps “this file is UTF-8”. It’s best to include it for Excel, but it’s sometimes better left out when importing into programs or web services.
Which encoding should I save as?
Choose “UTF-8 BOM” to open the file in Excel, “UTF-8” for Google Sheets or programs, and “Shift_JIS” if the system you’re importing into asks for it.
The encoding seems to be detected wrongly.
Detection can miss on short files or files with little Japanese text. Choose another encoding under “Read as” and the table is re-read instantly, so pick the one that isn’t garbled.
Some characters become “?” when I save as Shift_JIS.
Emoji, “𠮷” and some characters from other languages don’t exist in Shift_JIS. Before you save, those characters are shown along with the line where each first appears. To keep them, save as UTF-8, or replace them with other characters in the original data.
Can I use characters like ①, ㈱, 髙 and 﨑?
Yes. Shift_JIS is read and written in the form used on Windows (CP932, Windows-31J), so circled numbers, Roman numerals and variant kanji like 髙 stay as they are.
Should I change the line endings?
Usually “Keep as is” is fine. Only if the system you’re importing into requires it, choose “CRLF” for Windows or “LF” for Mac and Linux. Line breaks inside cells aren’t changed.
Does it work on my phone?
Yes. On iPhone you can choose CSV files from the Files app or from email attachments, and saved files go to Downloads in the Files app. Swipe the table sideways to see all the columns.
Does it work with TSV or TXT files?
Yes. Besides comma-separated files, it automatically recognizes tab- and semicolon-separated files and shows them as a table. It can also read Excel’s Unicode Text (UTF-16).
Is it free?
Yes. No sign-up or install, and no limits on file size or number of files. No ads, either.
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