Online tools
Free file converters from Duaer
Free Duaer tools for spreadsheets and data files: convert formats, merge, split, remove duplicates, fix encodings, and format JSON. Everything runs in your browser and no file is uploaded.
Tools
- CSV to Excel: detects UTF-8 or GBK and keeps long numbers as text.
- Excel to CSV: UTF-8 with BOM so Excel reopens it cleanly.
- JSON to CSV: nested fields become columns like `customer.name`.
- CSV to JSON: the first row becomes field names, one record per row.
- Markdown table to Excel: paste a table from an AI chat.
- Word table to Excel: one sheet per table in a .docx.
- PDF table to Excel: rebuilds rows and columns from text PDFs.
Clean up tables
- Merge Excel or CSV files: columns aligned by header, optional source-file column.
- Split a table by column: one sheet per department, region, or any column value.
- Remove duplicate rows: pick the columns that define a duplicate and keep the first row.
- GBK / UTF-8 converter: fix garbled CSV and TXT files either way.
- JSON formatter and validator: format, minify, and find the line and column of an error.
Where your file goes
These Duaer tools read the file and build the result inside your browser. Nothing passes through Duaer servers, and closing the tab discards the data.
Questions
Are the Duaer converters free?
Yes, and no sign-in is needed. You only register for Duaer when you want the conversion to run automatically as a digital organization.
Does Duaer upload my file?
No. The Duaer converters run in your browser, and the file never leaves your computer.
In this section
CSV to Excel converter (free, no upload)
A free Duaer tool that turns CSV into .xlsx in your browser. It detects UTF-8 or GBK, keeps long IDs as text, and never uploads the file.
File conversionExcel to CSV converter (UTF-8, no upload)
A free Duaer tool that turns .xlsx or .xls into UTF-8 CSV in your browser. Pick a sheet; a BOM is added by default so Excel reopens it cleanly.
File conversionJSON to CSV converter (nested JSON flattened)
A free Duaer tool: paste or upload JSON, nested fields become columns, and you download CSV or Excel. It runs in your browser with no upload.
File conversionCSV to JSON converter (free, no upload)
A free Duaer tool that turns each CSV row into a JSON object keyed by the header row. Optional number and boolean detection, GBK support, copy or download.
File conversionMarkdown table to Excel (works on AI chat tables)
A free Duaer tool: paste a Markdown table, including one from an AI chat reply, and download Excel or CSV. Several tables become several sheets.
File conversionWord table to Excel converter (.docx)
A free Duaer tool: open a .docx and every table in it becomes its own Excel sheet, with line breaks inside cells kept. No upload.
File conversionPDF table to Excel converter (text PDFs)
A free Duaer tool that reads text positions in a PDF and rebuilds table rows and columns as Excel, in your browser. Best for PDFs with selectable text; invoices and statements with varied layouts fit a Duaer extraction flow.
File conversionMerge Excel and CSV files online (columns matched by header)
A free Duaer tool: pick several Excel or CSV files, match columns by header name, and get one table with an optional source-file column. No upload.
File conversionSplit an Excel table by column online (one sheet per value)
A free Duaer tool: pick a column such as department, region, or store, and get one sheet per value, or download any group as CSV. No upload.
File conversionRemove duplicate rows from Excel or CSV online
A free Duaer tool: open an Excel or CSV file, pick the columns that define a duplicate, keep the first row, optionally ignore case and spaces, and see how many rows were removed. No upload.
File conversionGBK to UTF-8 converter online (fix garbled CSV and TXT)
A free Duaer tool that detects whether a file is GBK or UTF-8 and converts it to UTF-8 (with or without BOM) or GBK, fixing garbled Chinese in CSV, TXT, subtitle, and other text files. No upload.
File conversionJSON formatter and validator online (shows error line and column)
A free Duaer tool: paste or upload JSON to format or minify it, and see the exact line and column when it is invalid. Runs in your browser with no upload.