Free online Excel tools — private, in your browser.

Spreadsheet tools that never upload your data

excel.gumber.ai is a free collection of 20 Excel and CSV utilities. Merge and split workbooks, compare versions, run VLOOKUP, XLOOKUP and fuzzy lookups between files, remove duplicates, combine columns, mail merge, and convert between Excel, CSV, JSON, PDF and images. Every tool runs locally in your web browser — there is no server processing, no account and no upload queue.

Convert tools

• Excel to CSV — Convert XLSX/XLS sheets to CSV with your choice of delimiter. Export one sheet or all.
• CSV to Excel — Turn CSV, TSV or delimited text into a proper .xlsx workbook. Auto-detects delimiters and numbers.
• Excel to JSON — Convert spreadsheets to JSON arrays or objects. Supports nested keys like "address.city".
• JSON to Excel — Paste or upload JSON and get a clean spreadsheet. Nested objects are flattened into columns.
• PDF to Excel — Extract tables and text from digital PDFs into rows and columns.
• Image to Excel (OCR) — Read tables from screenshots, photos or scans and turn them into a spreadsheet.

Merge & Split tools

• Merge Excel Files — Combine multiple workbooks into one sheet or one workbook. Columns are matched by header name.
• CSV Merger — Join many CSV files into a single CSV, lining up columns by header.
• Excel Splitter — Split a workbook by sheet, by row count, into equal parts, or by the values in a column.

Clean, Compare & Lookup tools

• Compare Excel Files — Spot changed cells, added rows and removed rows between two versions of a sheet.
• Remove Duplicates — Find and remove duplicate rows based on all columns or just the ones you pick.
• Excel VLOOKUP — Pull matching values from a second table into your sheet — no formulas, no #REF errors.
• XLOOKUP / INDEX-MATCH — Look up any column in any direction and return one or many result columns.
• HLOOKUP Tool — Lookups for horizontal tables where headers run down the first column.
• Multi-Criteria Lookup — Match rows on two or more columns at once, e.g. Name + Date.
• Excel Fuzzy Lookup — Match names that are almost the same — typos, abbreviations and spacing differences.
• Combine Columns — Join two or more columns into one with any separator — e.g. First + Last name.
• Mail Merge — Generate personalised letters, emails or messages from a spreadsheet and a template.

View & Optimize tools

• Online Excel Viewer — Open XLSX, XLS, ODS and CSV files in your browser. Search and browse every sheet.
• Compress Excel — Shrink bloated XLSX/XLS files by rewriting them with maximum compression.

Limitations

• Everything runs in your browser’s memory, so the practical file size depends on your device. As a rough guide: up to ~50 MB or ~500,000 rows works well on a modern laptop; phones and tablets handle much less.
• Very large files can make the tab slow or crash. If that happens, split the file first or use a desktop computer.
• Outputs keep values and formulas’ results but not formatting, charts, images, pivot tables or macros.

See all limitations

Frequently asked questions