Free Online Yang Formatter - Beautify and structure Yang models

Easily clean and format Yang code online. Beautify your network configuration data models with our free yang formatter / yang beautifier - 2025.

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How to use online free YANG code formatter / YANG beautifier ?

  • Just paste your YANG code into the input and get ready! Any code you have copied elsewhere can be pasted in here
  • Once your YANG code is in place, click the FORMAT button. The tool will automatically organize your YANG code with proper indents and spacing, making it clean and easy to read.
  • You can also customize the tab size also, After changing it, hit FORMAT again to reformat your YANG code with the new spacing.
  • You can also print formatted code in PDF and download pdf by clicking on Print as PDF Button.
  • When you are happy with the results, you can copy the formatted YANG code. Either select and copy it manually or use the COPY button to copy everything instantly to your clipboard.
  • Want to format new code? Just click the CLEAR button to reset the input field and start again.
YANG code formatter

YANG Code Formatter – History, Syntax, Use Cases & Formatting Importance

1. What is YANG?

YANG (Yet Another Next Generation) is a data modeling language primarily used to model configuration and state data manipulated by network management protocols such as NETCONF and RESTCONF. Designed by the IETF (Internet Engineering Task Force), YANG plays a critical role in defining the structure of network configuration, operational state, and RPCs for networking devices.

YANG models are typically used to define how network devices (like routers, switches, and firewalls) can be configured programmatically. These models enable network automation, interoperability, and consistency across vendors and tools in modern networking environments.

YANG is not a programming language but a descriptive modeling language — similar to how XML or JSON defines data structure. However, like any structured format, well-formatted YANG is essential for clarity, debugging, and automation. That’s where a YANG code formatter becomes essential.

2. A Brief History of YANG

YANG was first introduced in RFC 6020 (2010) as a standardized data modeling language for NETCONF. It emerged out of the need for a unified modeling format to streamline network device configuration. Before YANG, vendors had proprietary schemas, making automation complex and error-prone.

Over time, YANG has evolved to support more than just NETCONF. The release of RFC 7950 (YANG 1.1) in 2016 expanded its capabilities, improving module versioning, import mechanisms, and extending its use into RESTCONF-based management.

Today, major networking vendors like Cisco, Juniper, Huawei, and Nokia use YANG models in their products. It’s also the backbone of network management in SDN (Software Defined Networking), NFV (Network Function Virtualization), and next-generation data centers.

3. YANG Code Example

module example-interfaces {
  namespace "http://example.com/interfaces";
  prefix "if";

  container interfaces {
    list interface {
      key "name";
      leaf name {
        type string;
      }
      leaf enabled {
        type boolean;
        default "true";
      }
    }
  }
}

In this example, YANG defines a module called example-interfaces that models a list of network interfaces, each with a name and an enabled flag. It’s structured, readable, and ideal for generating configuration data through protocols like NETCONF or RESTCONF.

4. Why Use a YANG Code Formatter?

YANG files are highly structured and often deeply nested. As models grow larger — incorporating hundreds of containers, leaves, and groupings — maintaining readability becomes a challenge. A proper YANG formatter helps resolve this by organizing blocks, aligning braces, and beautifying leaf definitions.

  • Improves Readability: Developers and network engineers can read and understand models more easily.
  • Standardizes Formatting: Ensures consistency across teams and tools.
  • Speeds Up Development: Eliminates formatting distractions while writing or editing models.
  • Reduces Errors: Helps identify misplaced braces, duplicate keys, or syntax inconsistencies.
  • Prepares for Review: Makes models presentable for audits, documentation, or peer review.

The YANG formatter at codeformatting.com allows engineers to quickly beautify YANG code online — no need to install YANG compilers or rely on CLI tools.

5. Advantages of YANG

  • Structured Data Modeling: Clearly defines configuration and state information for devices.
  • Vendor Neutral: Supported by all major networking vendors through standard models.
  • Extensible: Allows reuse through grouping and uses constructs.
  • Human Readable: Syntax is cleaner than XML or ASN.1 equivalents.
  • Protocol Compatible: Designed for use with NETCONF, RESTCONF, and other protocols.
  • Automation Ready: Easily converted into JSON, XML, or gRPC schemas for programmatic access.

6. Disadvantages of YANG

  • Learning Curve: YANG’s structure and terminology can be complex for beginners.
  • Tooling Required: Effective use often requires tools like pyang, yanglint, or netconfd.
  • Debugging is Tricky: Validation errors can be hard to trace without a proper formatter.
  • Lack of IDE Support: Limited support in popular code editors compared to languages like Python or JavaScript.
  • Verbose for Small Tasks: Overhead for modeling simple configurations.

7. Real-World Use Cases for YANG

  • Network Configuration: Define device settings such as interfaces, routes, and ACLs.
  • Operational State Monitoring: Model real-time device stats and health checks.
  • SDN Controllers: Use YANG models to manage virtualized network functions in data centers.
  • Vendor Interoperability: Build multi-vendor automation pipelines using standard models.
  • API Definition: Translate YANG into RESTCONF or gRPC schemas for network automation platforms.
  • Template Generation: Generate CLI commands or JSON/XML payloads from YANG models.

8. Popular Tools for Working with YANG

  • pyang: A Python-based parser and validator for YANG modules.
  • yanglint: C-based tool for validating and formatting YANG models.
  • ConfD: Commercial tool that uses YANG to generate NETCONF/RESTCONF agents.
  • YANG Explorer: GUI for browsing and testing YANG models.
  • YANG Suite: Network management suite developed by Cisco.

9. Why YANG Formatting Matters

While machines can parse YANG regardless of formatting, human readers need structure. Poorly formatted YANG modules are hard to debug, extend, or validate. A single misaligned leaf or forgotten semicolon can lead to cascading issues.

A YANG formatter eliminates ambiguity and enforces a clean layout for:

  • Module headers and metadata
  • Leaf and container hierarchies
  • Import/include declarations
  • Key-value types and descriptions

The online formatter at codeformatting.com makes this easy by letting you paste raw YANG code and receive a polished, indented version instantly.

10. Future of YANG

As network infrastructure becomes more software-defined and API-driven, YANG will continue to play a central role. It will remain a bridge between high-level orchestration platforms and low-level device configurations.

The OpenConfig initiative, for instance, relies heavily on YANG models to define vendor-neutral schemas. Organizations like ONF (Open Networking Foundation) and IETF continue to refine the YANG standard, expanding it into service orchestration, policy modeling, and beyond.

11. Conclusion

YANG is a critical technology for modern network automation. It brings consistency, structure, and standardization to device configuration and telemetry. As the complexity of networked systems grows, clear and formatted YANG models will become essential for scaling automation.

That’s why using a tool like the YANG code formatter at codeformatting.com is not just helpful — it’s necessary. Whether you're building your first YANG module or managing a multi-vendor SDN deployment, well-formatted code improves collaboration, validation, and documentation.

Paste your YANG schema, beautify it instantly, and focus on defining networks — not struggling with indentation or brace alignment.

Frequently Asked Questions

What is the difference between a code formatter and a linter?

A code formatter focuses on fixing the style and structure of the code, while a linter identifies potential errors, bugs, or non-compliance with best practices.

Can a YANG formatter / YANG beautifier break my code?

A properly implemented YANG code formatter won't change the logic of your code. However, if the code contains syntax errors, the formatter may fail or produce unexpected results.

Can I customize a YANG formatter / YANG beautifier?

Yes, most online code formatters allow customization through configuration files, tab sizes, and other preferences.

Should I format code before or after writing tests?

It’s a good practice to format your code continuously. Many developers integrate formatters into their editors to apply changes on save.

Are code formatters language-specific?

Some formatters are language-specific (e.g., Black for Python), while others support multiple languages (e.g., Prettier).

How do I know which Code formatter is best for my project?

Consider the primary language, team preferences, and integration capabilities when choosing a formatter.