Excelize — High-Performance Go Library for Excel Spreadsheets

Introduction

Excelize provides a pure Go implementation for reading and writing Office Open XML spreadsheet files. It lets backend services generate complex Excel reports, import user-uploaded spreadsheets, and process large datasets without relying on external binaries or COM automation.

What Excelize Does

• Reads and writes XLSX, XLSM, and XLTM files with full formula support
• Creates charts (bar, line, pie, scatter, and 50+ chart types)
• Generates pivot tables and applies conditional formatting rules
• Embeds images, shapes, and comments into cells
• Streams rows for writing spreadsheets with millions of rows in constant memory

Architecture Overview

Excelize operates on the underlying ZIP-packaged XML structure of Office Open XML files. It parses shared strings, style sheets, and worksheet XML into in-memory Go structs, applies edits, then serializes back to valid OOXML. The streaming writer bypasses full in-memory representation by flushing rows directly to the output, enabling constant-memory writes for large files.

Self-Hosting & Configuration

• Install via go get github.com/xuri/excelize/v2
• Zero external dependencies beyond the Go standard library
• Use StreamWriter for files exceeding available RAM
• Set default fonts, number formats, and date styles via Style structs
• Supports password-protected workbook decryption

Key Features

• Pure Go with no CGO or system dependencies
• Streaming writer handles millions of rows in constant memory
• 170+ formula functions evaluated natively
• 50+ chart types with full customization
• Thread-safe concurrent read access to workbooks

Comparison with Similar Tools

• Apache POI (Java) — mature but requires JVM; Excelize is a single Go binary
• openpyxl (Python) — Python-only; Excelize integrates into Go services natively
• SheetJS (JS) — browser-focused; Excelize targets server-side batch processing
• xlsx2csv — read-only conversion; Excelize supports full read-write-chart workflows
• Google Sheets API — cloud-dependent; Excelize works fully offline

FAQ

Q: Can Excelize handle very large files? A: Yes, the StreamWriter API writes rows incrementally, keeping memory constant regardless of row count.

Q: Does it support formulas? A: Excelize supports setting formula strings and evaluating 170+ built-in functions.

Q: Is Excelize thread-safe? A: Concurrent reads are safe. Writes to a single file should be serialized.

Q: Can I read password-protected Excel files? A: Yes, Excelize supports decrypting workbooks protected with a password.

Sources

• https://github.com/qax-os/excelize
• https://xuri.me/excelize/