A minimal, lightweight .NET library for converting office files to PDF.

👉 Online Demo — Try it in your browser, no install required.

⚠️ Due to limited fonts available in the browser, the rendering results may not be optimal. For the best experience, please test locally on your machine.

• Excel-to-PDF — Convert .xlsx files to PDF
• Word-to-PDF — Convert .docx files to PDF
• Minimal dependencies — Lightweight; relies almost entirely on built-in .NET APIs
• Serverless-ready — No COM, no Office installation, no Adobe Acrobat — runs anywhere .NET runs
• Native AOT — Pre-compiled standalone binaries for Windows / Linux / macOS; no .NET runtime required
• Valid PDF 1.4 output
• 100% open-source & free — Apache 2.0 licensed, commercial use welcome; just keep the attribution. PRs & contributions are even better!
• Chart — Not currently supported well

Note: MiniPdf currently only handles basic conversions. Complex or highly customized Office documents may not convert perfectly. If you encounter compatibility issues, please open an Issue or submit a Pull Request — contributions are very welcome!

• Trained small LLM by Apache POI + LibreOffice
• AI development by GitHub Copilot + Claude Code

dotnet add package MiniPdf

using MiniSoftware;

// Excel to PDF
MiniPdf.ConvertToPdf("data.xlsx", "output.pdf");

// Word to PDF
MiniPdf.ConvertToPdf("report.docx", "output.pdf");

// File to byte array
byte[] pdfBytes = MiniPdf.ConvertToPdf("data.xlsx");

// Stream to byte array
using var stream = File.OpenRead("data.xlsx");
byte[] pdfBytes = MiniPdf.ConvertToPdf(stream);

If your environment has limited system fonts (for example, containers or Blazor WASM), register fonts before conversion.

using MiniSoftware;

// Register one or more fonts at app startup.
MiniPdf.RegisterFont("NotoSansSC", File.ReadAllBytes("Fonts/NotoSansSC-Regular.ttf"));
MiniPdf.RegisterFont("NotoColorEmoji", File.ReadAllBytes("Fonts/NotoColorEmoji.ttf"));

MiniPdf.ConvertToPdf("report.docx", "report.pdf");

Notes:

• Supported input bytes are TrueType .ttf and TrueType Collection .ttc.
• Register fonts once during startup to avoid duplicate registrations.
• Registered fonts are prioritized before system fonts.

MiniPdf also provides a command-line tool — MiniPdf.Cli — for quick conversion without writing code.

An experimental Rust rewrite is available under minipdf-rs. It contains a minipdf library crate and a Rust CLI with the same basic command shape as the .NET tool. The Rust version currently supports basic .xlsx and .docx text extraction and PDF generation, and is not yet feature-equivalent with the .NET implementation.

dotnet tool install --global MiniPdf.Cli

# Convert Excel to PDF (output: data.pdf)
minipdf data.xlsx

# Convert Word to PDF
minipdf report.docx

# Specify output path
minipdf report.docx -o /path/to/output.pdf

# Register custom fonts (for containers / headless environments)
minipdf report.docx --fonts ./Fonts

MiniPdf.Cli supports Native AOT (Ahead-of-Time) compilation — C# code is compiled directly into native machine code at build time, just like C/C++, producing a standalone executable. No .NET runtime or JIT compiler is needed at run time.

Advantages:

• Zero dependencies — no .NET SDK or runtime needed on the target machine
• Instant startup — native machine code, no JIT warm-up
• Small footprint — single-file binary, easy to distribute and deploy
• CI/CD friendly — download and run in any pipeline without installing .NET

Download: grab the binary for your platform from the GitHub Releases page.

Usage (example on Linux / macOS):

# Download & extract
tar -xzf minipdf-linux-x64.tar.gz

# Convert
./minipdf report.docx -o report.pdf

Usage (example on Windows):

# Extract the zip, then run
.\minipdf.exe report.docx -o report.pdf

MiniPdf output is compared against MiniExcel and Office 365 as the reference renderers across 373 test cases.

Scoring: text similarity 40% + visual similarity 40% + page count 20%

• XLSX Benchmark Report — XLSX conversion test cases
• DOCX Benchmark Report — DOCX conversion test cases
• Issue Files Xlsx Report — Real-world issue file test cases
• Issue Files Docx Report — Real-world issue file test cases

All test cases comparing MiniPdf output vs MiniExcel / Office 365 reference. Page 1 shown for multi-page results.

MiniPdf	MiniExcel / Office 365 (Reference)
classic01	Basic table with headers 🟢 99.9%
classic02	Multiple worksheets 🟢 99.8%
classic03	Empty workbook 🟢 100.0%
classic04	Single cell 🟢 100.0%
classic05	Wide table 🟢 99.8%
classic06	Tall table 🟢 97.8%
classic07	Numbers only 🟢 100.0%
classic08	Mixed text and numbers 🟢 99.9%
classic09	Long text 🟢 98.4%
classic10	Special xml characters 🟢 99.9%
classic11	Sparse rows 🟢 100.0%
classic12	Sparse columns 🟢 99.9%
classic13	Date strings 🟢 99.9%
classic14	Decimal numbers 🟢 99.9%
classic15	Negative numbers 🟢 99.9%
classic16	Percentage strings 🟢 99.4%
classic17	Currency strings 🟢 99.9%
classic18	Large dataset 🟢 95.7%
classic19	Single column list 🟢 99.9%
classic20	All empty cells 🟢 100.0%
classic21	Header only 🟢 99.9%
classic22	Long sheet name 🟢 99.9%
classic23	Unicode text 🟢 91.3%
classic24	Red text 🟢 99.9%
classic25	Multiple colors 🟢 99.8%
classic26	Inline strings 🟢 99.9%
classic27	Single row 🟢 99.9%
classic28	Duplicate values 🟢 99.9%
classic29	Formula results 🟢 99.9%
classic30	Mixed empty and filled sheets 🟢 100.0%
classic31	Bold header row 🟢 99.9%
classic32	Right aligned numbers 🟢 99.9%
classic33	Centered text 🟢 99.9%
classic34	Explicit column widths 🟢 99.9%
classic35	Explicit row heights 🟢 99.5%
classic36	Merged cells 🟢 99.9%
classic37	Freeze panes 🟢 99.6%
classic38	Hyperlink cell 🟢 99.9%
classic39	Financial table 🟢 99.8%
classic40	Scientific notation 🟢 99.9%
classic41	Integer vs float 🟢 99.9%
classic42	Boolean values 🟢 99.6%
classic43	Inventory report 🟢 99.5%
classic44	Employee roster 🟢 98.0%
classic45	Sales by region 🟢 99.9%
classic46	Grade book 🟢 99.6%
classic47	Time series 🟢 99.3%
classic48	Survey results 🟢 99.6%
classic49	Contact list 🟢 98.5%
classic50	Budget vs actuals 🟢 99.6%
classic51	Product catalog 🟢 98.5%
classic52	Pivot summary 🟢 99.6%
classic53	Invoice 🟢 99.5%
classic54	Multi level header 🟢 99.8%
classic55	Error values 🟢 99.8%
classic56	Alternating row colors 🟢 99.6%
classic57	Cjk only 🟢 91.1%
classic58	Mixed numeric formats 🟢 99.5%
classic59	Multi sheet summary 🟢 99.9%
classic60	Large wide table 🟢 97.4%
classic61	Product card with image 🟢 99.9%
classic62	Company logo header 🟢 99.6%
classic63	Two products side by side 🟢 99.8%
classic64	Employee directory with photo 🟢 99.1%
classic65	Inventory with product photos 🟢 99.4%
classic66	Invoice with logo 🟢 99.2%
classic67	Real estate listing 🟢 99.8%
classic68	Restaurant menu 🟢 98.6%
classic69	Image only sheet 🟢 100.0%
classic70	Product catalog with images 🟢 99.2%
classic71	Multi sheet with images 🟢 99.8%
classic72	Bar chart image with data 🟢 99.5%
classic73	Event flyer with banner 🟢 99.6%
classic74	Dashboard with kpi image 🟢 97.9%
classic75	Certificate with seal 🟢 99.5%
classic76	Product image grid 🟢 99.7%
classic77	News article with hero image 🟢 99.6%
classic78	Small icon per row 🟢 99.2%
classic79	Wide panoramic banner 🟢 99.8%
classic80	Portrait tall image 🟢 99.8%
classic81	Step by step with images 🟢 99.7%
classic82	Before after images 🟢 99.4%
classic83	Color swatch palette 🟢 99.4%
classic84	Travel destination cards 🟢 99.6%
classic85	Lab results with image 🟢 99.2%
classic86	Software screenshot features 🟢 98.7%
classic87	Sports results with logos 🟢 99.8%
classic88	Image after data 🟢 99.7%
classic89	Nutrition label with image 🟢 99.5%
classic90	Project status with milestones 🟢 99.0%
classic91	Simple bar chart 🟢 96.6%
classic92	Horizontal bar chart 🟢 96.9%
classic93	Line chart 🟢 93.2%
classic94	Pie chart 🟢 97.2%
classic95	Area chart 🟡 76.4%
classic96	Scatter chart 🟢 94.8%
classic97	Doughnut chart 🟢 97.5%
classic98	Radar chart 🟢 95.1%
classic99	Bubble chart 🟢 92.0%
classic100	Stacked bar chart 🟢 95.0%
classic101	Percent stacked bar 🟢 93.6%
classic102	Line chart with markers 🟢 93.0%
classic103	Pie chart with labels 🟡 86.9%
classic104	Combo bar line chart 🟡 81.6%
classic105	3d bar chart 🟡 85.8%
classic106	3d pie chart 🟢 96.7%
classic107	Multi series line 🟡 80.6%
classic108	Stacked area chart 🟢 94.4%
classic109	Scatter with trendline 🟢 92.3%
classic110	Chart with legend 🟡 84.7%
classic111	Chart with axis labels 🟢 92.1%
classic112	Multiple charts 🟡 85.4%
classic113	Chart sheet 🟡 86.4%
classic114	Chart large dataset 🟢 91.6%
classic115	Chart negative values 🟢 92.1%
classic116	Percent stacked area 🟢 93.8%
classic117	Stock ohlc chart 🟡 80.9%
classic118	Bar chart custom colors 🟢 95.5%
classic119	Dashboard multi charts 🟢 92.1%
classic120	Chart with date axis 🟡 76.1%
classic121	Thin borders 🟢 99.7%
classic122	Thick outer thin inner 🟢 99.6%
classic123	Dashed borders 🟢 99.1%
classic124	Colored borders 🟢 99.7%
classic125	Solid fills 🟢 99.2%
classic126	Dark header 🟢 99.5%
classic127	Font styles 🟢 99.6%
classic128	Font sizes 🟢 99.0%
classic129	Alignment combos 🟢 99.8%
classic130	Wrap and indent 🟢 99.5%
classic131	Number formats 🟢 99.6%
classic132	Striped table 🟢 99.0%
classic133	Gradient rows 🟢 99.6%
classic134	Heatmap 🟢 98.8%
classic135	Bottom border only 🟢 99.8%
classic136	Financial report styled 🟢 99.3%
classic137	Checkerboard 🟢 98.4%
classic138	Color grid 🟢 99.4%
classic139	Pattern fills 🟢 99.2%
classic140	Rotated text 🟢 98.1%
classic141	Mixed edge borders 🟢 99.7%
classic142	Styled invoice 🟢 98.3%
classic143	Colored tabs 🟢 100.0%
classic144	Note style cells 🟢 99.6%
classic145	Status badges 🟢 99.1%
classic146	Double border table 🟢 99.6%
classic147	Multi sheet styled 🟢 99.7%
classic148	Frozen styled grid 🟢 97.3%
classic149	Merged styled sections 🟢 98.7%
classic150	Kitchen sink styles 🟢 97.5%
classic151	Multilingual greetings 🟢 93.5%
classic152	Emoji sampler 🟢 91.1%
classic153	Currency symbols 🟢 98.5%
classic154	Math symbols 🟢 95.7%
classic155	Diacritical marks 🟢 99.8%
classic156	Rtl bidi text 🟡 84.0%
classic157	Cjk extended 🟢 91.3%
classic158	Emoji skin tones 🟢 99.3%
classic159	Zwj emoji 🟢 90.6%
classic160	Punctuation marks 🟢 94.4%
classic161	Box drawing 🟢 95.0%
classic162	Cjk emoji styled 🟡 86.5%
classic163	Cyrillic alphabets 🟢 99.6%
classic164	Indic scripts 🟡 87.4%
classic165	Southeast asian 🟢 96.0%
classic166	Emoji progress 🟢 98.6%
classic167	Musical symbols 🟢 90.0%
classic168	Mixed ltr rtl styled 🟢 94.5%
classic169	Korean invoice 🟡 88.4%
classic170	Emoji dashboard 🟢 96.3%
classic171	Ipa phonetic 🟢 97.6%
classic172	Emoji timeline 🟢 95.3%
classic173	African languages 🟢 90.8%
classic174	Technical symbols 🟢 94.4%
classic175	Multiscript catalog 🟢 92.6%
classic176	Combining characters 🟢 94.5%
classic177	Emoji calendar 🟡 88.4%
classic178	Caucasus ethiopic 🟢 96.9%
classic179	Emoji inventory 🟢 91.0%
classic180	Polyglot paragraph 🟢 93.6%
classic181	Feedback tracker with images 🟢 99.4%
classic182	Dense long text columns 🟢 96.5%
classic183	Mixed content grid 🟢 99.4%
classic184	Wide narrow columns 🟢 98.4%
classic185	Tall rows vertical align 🟢 99.7%
classic186	Multi sheet image report 🟢 99.6%
classic187	Bug report with screenshots 🟢 98.2%
classic188	Merged header with images 🟢 99.5%
classic189	Alternating image text rows 🟢 95.3%
classic190	Dashboard kpi images 🟢 99.5%
classic191	Payroll calculator 🟡 89.5%

This project is licensed under the Apache License 2.0.