Add your XLS file
Drop one or more .xls files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Converting a .xls file to .csv extracts the document's content from its office package into a portable form. Free, private, and validated — the file never leaves your browser.
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.Converting a .xls file to .csv extracts the document's content from its office package into a portable form. An .xls file is a legacy Microsoft Excel workbook in the binary BIFF format, Excel's default from its earliest releases through Excel 2003. Each sheet is a stream of typed binary records — cells, formulas, formats — rather than anything textual.
A .csv file is a comma-separated values table: plain-text rows with commas between fields, optionally quoted. It is probably the most widely produced data format in existence, emitted by everything from banking portals to lab instruments. For this route the practical draw is supported by effectively every data tool ever written and human-readable and hand-editable in a pinch — balanced against no type information — Excel famously strips leading zeros and mangles dates on open, which is worth knowing before you commit a large batch.
The practical trigger for this conversion is usually a mismatch: with .xls, the 65,536-row ceiling truncates modern datasets. Switching to .csv buys you supported by effectively every data tool ever written, which is why it is the better fit for exports from databases, CRMs, and banking systems. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
| Aspect | Excel workbook (.xls) | CSV table (.csv) |
|---|---|---|
| Format type | Text-based — characters and structure, so there is no visual quality loss | Text-based — characters and structure, so there is no visual quality loss |
| How it stores data | composed of typed binary records (id, length, payload) — LABELSST for shared-string cells, FORMULA for calculations, and hundreds more | fields containing commas, quotes, or newlines are wrapped in double quotes with embedded quotes doubled — the rule that breaks every naive split-on-comma parser |
| Strongest at | reading exports from ERP, banking, and lab systems that still emit .xls | exports from databases, CRMs, and banking systems |
| Weak spot | the 65,536-row ceiling truncates modern datasets | no type information — Excel famously strips leading zeros and mangles dates on open |
Drop one or more .xls files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Select .csv in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if CSV is selectable, the route is real and validated.
Press Convert. The package is unzipped in memory and its XML content parsed locally; nothing is uploaded.
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid CSV file. Outputs keep the original filename with the .csv extension.
There is no visual quality to lose — xls is text-oriented and csv is text-oriented, so the question is structural fidelity. Text, ordering, and basic structure are preserved; complex layout, embedded objects, and styling beyond the target's model are simplified.
Yes — the .xls file is processed inside your browser tab and never uploaded. The package is unzipped in memory and its XML content parsed locally; nothing is uploaded. Close the tab and the file is gone from memory.
Every spreadsheet, database, and programming language handles CSV, and browsers or text editors open it as plain text. The catch is dialect drift: delimiter, encoding, and quoting choices differ enough that robust importers always offer manual overrides.
It depends on the content: fields containing commas, quotes, or newlines are wrapped in double quotes with embedded quotes doubled — the rule that breaks every naive split-on-comma parser. Convert one representative file first and compare before batch-processing a large set.
In .xls, summaryInformation streams in the compound file record author, company, and creation and modification timestamps. Re-encoding through the browser pipeline does not carry embedded metadata into the output, which doubles as a privacy scrub — check the exported file if you specifically need tags preserved.