Feature Comparison

Choosing an Excel generation library is a long-term decision. This page compares XLFill against the most prominent alternatives across languages so you can make an informed choice.

The contenders

Library	Language	Approach	License
XLFill	Go	Template-first	MIT (free)
JXLS	Java	Template-first	Apache 2.0 (free)
EPPlus	.NET (C#)	Code-first	Polyform (paid for commercial)
XlsxWriter	Python	Code-first	BSD (free)
Aspose.Cells	Multi (.NET/Java/Python)	Code-first	Commercial ($999+/yr)

Feature matrix

Template and design

Feature	XLFill	JXLS	EPPlus	XlsxWriter	Aspose
Template-first design	Yes	Yes	No	No	Partial
Design in Excel (WYSIWYG)	Yes	Yes	No	No	No
Non-developers can edit templates	Yes	Yes	No	No	No
Expression language	expr-lang	JEXL	N/A	N/A	N/A
Custom expression delimiters	Yes	No	N/A	N/A	N/A
Template validation (no data needed)	Yes	No	N/A	N/A	N/A
Template-data contract validation	Yes	No	N/A	N/A	N/A

XLFill and JXLS share the template-first philosophy. The difference: XLFill adds pre-processing validation that JXLS lacks — catch template errors in CI before they reach production.

Commands and directives

Feature	XLFill	JXLS	EPPlus	XlsxWriter	Aspose
Loop (each/forEach)	20 commands	8 commands	Code	Code	Code
Conditional areas	jx:if	jx:if	Code	Code	Code
Fixed-count repeat	jx:repeat	No	Code	Code	Code
Grid/pivot layout	jx:grid	jx:grid	Code	Code	Code
Image embedding	jx:image	jx:image	Code	Code	Code
Cell merging in loops	jx:mergeCells	jx:mergeCells	Code	Code	Code
Template composition	jx:include	No	N/A	N/A	N/A
Loop filter/sort/group	Built-in	Partial	Code	Code	Code
Multisheet generation	Built-in	Partial	Code	Code	Code

XLFill’s jx:each has select, orderBy, groupBy, and multisheet built into the command attributes. JXLS requires custom Java code for most of these.

Data presentation

Feature	XLFill	JXLS	EPPlus	XlsxWriter	Aspose
Structured tables	jx:table	No	Code	Code	Code
Charts (bar/line/pie)	jx:chart	No	Code	Code	Code
Sparklines	jx:sparkline	No	No	Code	Code
Conditional formatting	jx:conditionalFormat	No	Code	Code	Code
Data validation/dropdowns	jx:dataValidation	No	Code	Code	Code
Named ranges	jx:definedName	No	Code	Code	Code

This is where XLFill pulls ahead of JXLS decisively. Charts, tables, conditional formatting, sparklines, data validation, and named ranges are all template commands in XLFill. In JXLS, none of these exist — you’d need to manipulate the output file with Apache POI after JXLS runs.

Layout and formatting

Feature	XLFill	JXLS	EPPlus	XlsxWriter	Aspose
Auto row height	jx:autoRowHeight	No	Code	Code	Code
Auto column width	jx:autoColWidth	No	Code	Code	Code
Freeze panes	jx:freezePanes	No	Code	Code	Code
Page breaks	jx:pageBreak	No	Code	Code	Code
Row grouping/outline	jx:group	No	Code	Code	Code
Sheet protection	jx:protect	No	Code	Code	Code
Formula expansion	Automatic	Partial	Manual	Manual	Manual

Every layout feature in XLFill is a zero-code template command. In EPPlus, XlsxWriter, and Aspose, every one of these requires explicit API calls in your application code.

Built-in functions

Feature	XLFill	JXLS	EPPlus	XlsxWriter	Aspose
Text transforms (upper/lower/title)	Built-in	No	N/A	N/A	N/A
Number/date formatting	Built-in	No	N/A	N/A	N/A
Null-safe helpers (coalesce/ifEmpty)	Built-in	No	N/A	N/A	N/A
Aggregation (sumBy/avgBy/countBy/minBy/maxBy)	Built-in	No	N/A	N/A	N/A
Hyperlinks in expressions	Built-in	No	Code	Code	Code
Cell comments in expressions	Built-in	No	Code	Code	Code
i18n/translations	Built-in (t())	No	N/A	N/A	N/A
Custom functions	WithFunction	Custom	N/A	N/A	N/A

18 built-in functions cover the most common expression needs. Custom functions are a single WithFunction call.

Performance and scaling

Feature	XLFill	JXLS	EPPlus	XlsxWriter	Aspose
Streaming mode	3x faster, 60% less memory	No	Yes	Yes (default)	Yes
Parallel processing	Built-in	No	No	No	No
Auto-mode (optimal strategy)	Built-in	No	No	No	No
Compiled/cached templates	Built-in	No	N/A	N/A	N/A
Batch generation	FillBatch	No	Code	Code	Code
Progress reporting	Built-in	No	No	No	No
Context cancellation	Built-in	No	No	No	No
1K rows throughput	~112K rows/sec (streaming)	~10K rows/sec	~50K rows/sec	~80K rows/sec	~60K rows/sec

XLFill is the only template engine with streaming, parallel, and auto-mode built in. Compiled templates eliminate file I/O for batch workloads. Go’s goroutine-based parallelism scales better than thread-based alternatives.

Error handling and DX

Feature	XLFill	JXLS	EPPlus	XlsxWriter	Aspose
Structured errors (kind + cell + message)	Yes	No	Partial	No	Partial
”Did you mean?” suggestions	Yes	No	No	No	No
Template validation (pre-fill)	Yes	No	N/A	N/A	N/A
Data contract validation	Yes	No	N/A	N/A	N/A
Debug trace output	Yes	No	No	No	No
Template description/introspection	Yes	No	N/A	N/A	N/A
Type safety (Go)	Compile-time	Runtime (Java)	Compile-time	Runtime	Mixed
HTTP handler	Built-in	No	No	No	No

XLFill’s developer experience is designed for production: catch errors before they reach users, get actionable diagnostics when something goes wrong, and serve reports directly from HTTP handlers.

API surface

Feature	XLFill	JXLS	EPPlus	XlsxWriter	Aspose
One-call fill	Yes	Yes	No	No	No
io.Reader/Writer support	Yes	Partial	Yes	No	Yes
HTTP handler	Built-in	No	No	No	No
Batch API	FillBatch	No	No	No	No
Data helpers (struct/JSON/SQL)	Built-in	No	No	No	No
Custom command registration	Yes	Yes	N/A	N/A	N/A
Area/style listeners	Yes	Yes	N/A	N/A	N/A

Pricing

	XLFill	JXLS	EPPlus	XlsxWriter	Aspose
Open source	MIT	Apache 2.0	Polyform	BSD	No
Free for commercial use	Yes	Yes	No (requires license)	Yes	No
Annual cost	$0	$0	~$300/dev	$0	~$999-$2,399/dev

When to choose XLFill

Choose XLFill when you:

• Write Go and want the fastest path from data to Excel
• Need non-developers (analysts, finance, operations) to own template design
• Want charts, tables, conditional formatting, and data validation without writing code
• Need streaming performance for large reports (10K+ rows)
• Want pre-fill validation and structured error handling
• Need batch generation or HTTP serving built in

Choose JXLS when you:

• Are in a Java ecosystem and cannot use Go
• Need only basic looping and conditional areas (no charts, tables, etc.)

Choose EPPlus/XlsxWriter/Aspose when you:

• Need fine-grained programmatic control over every cell
• Are building a spreadsheet editor, not a report generator
• Have an existing large codebase in .NET or Python

What’s next?

Ready to get started?

Getting Started →

Or see how templates work:

How Templates Work →