Coming from MiniExcel

MiniExcel moves rows of data and dictionaries in and out of XLSX and CSV with static methods and fills workbook templates. OneDocument has the same one-call shape for typed rows (Spreadsheet.Read<T> / Write), a forward-only cursor for the lowest-level streaming, the full workbook model when you need cells and styles, and Template.Render for templates. Read README.md first for what is true on every page.

Typed rows

// MiniExcel
MiniExcel.SaveAs(path, orders);
IEnumerable<Order> back = MiniExcel.Query<Order>(path);

// OneDocument: Order is a partial class or record marked [SpreadsheetRow]
Spreadsheet.Write(path, orders);                 // .xlsx, .csv or .tsv by extension
IEnumerable<Order> back = Spreadsheet.Read<Order>(path);

MiniExcel binds by reflection at run time; OneDocument binds with code generated when you compile, so it works under trimming and NativeAOT. Column names, order, formats and ignoring are attributes on the members ([SpreadsheetColumn], docs/spreadsheets-poco.md). Asynchronous forms: Spreadsheet.ReadAsync<T> and WriteAsync.

Untyped rows

// MiniExcel
foreach (dynamic row in MiniExcel.Query(path)) { Console.WriteLine(row.A); }

// OneDocument: one object array per row, no dynamic
foreach (object?[] row in Spreadsheet.ReadRows(path, sheet: "Sheet1")) { Console.WriteLine(row[0]); }

Writing dictionaries and tables

MiniExcel's SaveAs also takes dictionaries and DataTable/IDataReader. In OneDocument, write a typed record, or open a Workbook and set cells, or use the streaming writer:

// OneDocument: streaming write, constant memory
using XlsxStreamWriter book = XlsxStreamWriter.Create(path);
SheetStreamWriter sheet = book.AddSheet("Data");
foreach (Order o in orders)
{
    sheet.BeginRow();
    sheet.WriteNumber(o.Id);
    sheet.WriteText(o.Customer);
}
 
sheet.Complete();
book.Finish();

Templates

// MiniExcel
MiniExcel.SaveAsByTemplate(outPath, templatePath, new { Title = "Report", Items = items });

// OneDocument
Template.Render(templatePath, new Report { Title = "Report", Items = items }, outPath);

The data type is marked [TemplateModel] (generated binding), or pass a dictionary, JSON or a DataTable. Tags are {{ title }} and {% for item in items %} with Excel formulas as expressions (docs/templating.md, docs/templating-xlsx.md); MiniExcel's own template syntax is not read, so templates are rewritten once. The same call fills .docx and .pptx templates.

CSV

// MiniExcel
MiniExcel.SaveAs("out.csv", orders);

// OneDocument
Spreadsheet.Write("out.csv", orders);            // formula-injection safe by default; delimiter detected on read

CSV details: docs/csv.md.

Not supported or different

• No QueryAsDataTable or GetSheetNames statics: open a Workbook (wb.Sheets) or use XlsxStreamReader.
• No dynamic rows and no Dictionary<string, object> output from the typed binding.
• No MiniExcel.Insert (append to an existing file); open the workbook, add rows, save.
• No image or chart embedding option on SaveAs; the template engine inserts pictures ({% image %}).
• Typed binding needs partial types marked [SpreadsheetRow], so types you do not own cannot be bound directly; map them to a record you own.