Json to FHIR Convertor

Convert JSON to FHIR in Seconds with Our AI-Powered Converter

Alireza (Elijah) Emami

Alireza Emami

Software Engineer

.6 min read

.1 November, 2025

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Whitefox AI-powered JSON to FHIR Converter instantly transforms any legacy or custom JSON structure into validated, FHIR-compliant resources. This online converter automates complex FHIR mapping and data transformation processes with no setup, no manual mapping. Designed for developers, researchers, and healthcare innovators, It provides HL7-compliant support aligned with supported regional standards.

AI-Powered JSON to FHIR Converter (Online Tool)

The AI-Powered JSON to FHIR Converter lets you upload any JSON file including legacy, custom, or API-based ones and automatically generate valid FHIR resources. This automated online converter removes manual mapping and provides ready-to-use output validated for HL7 compatibility.

What is FHIR (Overview)

FHIR (Fast Healthcare Interoperability Resources) is an open standard created by HL7 (Health Level Seven International) to enable healthcare systems to exchange data seamlessly and consistently. It provides a unified, web-based framework for sharing clinical and administrative information across hospitals, clinics, labs, and mobile apps. It describes a set of modular data structures called resources, which represent common healthcare entities such as patients, medications, observations, and encounters. Each resource has a defined format and meaning, allowing different systems to exchange and interpret clinical information consistently.

Try our free online JSON to FHIR converter today at
converter.fhir.whitefox.cloud
the fastest way to achieve automated FHIR mapping, seamless HL7 compatibility,
and instant data transformation from any legacy JSON format.

Older Healthcare Data Standards

Before FHIR, data exchange in healthcare was largely handled using HL7 Version 2 and Version 3, as well as CDA (Clinical Document Architecture).

  • HL7 v2, a standard that dates back to the late 1980s, was simple and widely adopted but lacked semantic consistency by relying on text-based messages.

  • HL7 v3 introduced a more formal structure based on XML and the Reference Information Model (RIM), but it was difficult to implement and had low adoption due to complexity and failed its mission.

  • CDA standardized the structure of clinical documents (like discharge summaries) but was document-centric, which limited its flexibility in exchanging granular data.

FHIR was created as a response to these limitations, combining HL7’s rich data modeling with modern API architecture. It supports RESTful APIs and common web data encodings like JSON and XML, making it easy to use for developers familiar with web technologies.

FHIR Core Profiles and Extensions

While FHIR provides a global base specification which defines common, standardized representations of healthcare resources to ensure baseline interoperability, every country has its own healthcare workflows, regulations, and data standards. To address these variations, FHIR Implementation Guides (IGs) such as US Core, AU Core, and UK Core define national extensions and constraints to the base FHIR model.

  • US Core defines how FHIR should be implemented in the United States, aligned with regulations like the ONC Cures Act and the U.S. Core Data for Interoperability (USCDI).

  • AU Core adapts FHIR for the Australian healthcare system, ensuring alignment with local standards like My Health Record (MHR) and Australian privacy laws.

  • UK Core defines profiles that align with the NHS Digital ecosystem in the United Kingdom.

This profiling mechanism allows global adaptability which means any healthcare system can build compatible specifications on top of the standard core.

FHIR Integration

Integrating with FHIR means enabling your healthcare applications to exchange data using FHIR resources and APIs. Rather than reinventing how healthcare data is stored or transferred, FHIR defines a common “grammar” that systems can adopt to talk to each other efficiently, securely, consistently, and in real time across different platforms.​

Integrating with FHIR often requires manual FHIR mapping or custom scripts for data transformation, our automated converter eliminates that complexity.

How FHIR Integration Works

At its core, FHIR is built on RESTful API principles just like modern web apps. Each FHIR Resource (such as Patient, Practitioner, or Organization) can be accessed or modified via standard HTTP operations:

  • GET → Retrieve data (e.g., fetch patient information)

  • POST → Create new resources (e.g., record a new observation)

  • PUT/PATCH → Update existing data

  • DELETE → Remove a record

Because of this simplicity, FHIR can easily be integrated into web apps, cloud systems, or even IoT devices.

System Architecture

The FHIR Server acts as the “brain” of the system by storing and exposing FHIR resources through APIs.

Legacy data sources feed into this system through integration layers or adapters that transform old formats into FHIR-compatible structures.

This is exactly where the FHIR AI Converter, an online free json to fhir converter, fits in by automating and simplifying the transformation from legacy data (like raw JSON objects) into valid FHIR resources. Integration can be achieved in different ways:

  • FHIR Sidecar Approach: Implement an adapter that connects legacy databases to a FHIR server through Pub/Sub or message queues.

  • Native FHIR Server: Store and serve all healthcare data in FHIR format using cloud-native or containerized deployment (e.g., Kubernetes or Azure Health Data Services).

  • Middleware Translator: A lightweight intermediary service like the FHIR AI Converter that translates non-FHIR data into FHIR-compatible JSON for downstream systems.​

The FHIR AI Converter, an online json to fhir converter, automates data transformation between legacy systems and modern HL7-compatible FHIR servers.

Key Considerations for Integration

When building or integrating with FHIR, developers should pay attention to:

  • FHIR Versioning: Ensure compatibility with the FHIR version (e.g., R4, R5).

  • Implementation Guides (Cores): Follow the appropriate national FHIR Core (e.g., US Core, AU Core) for regulatory compliance.

  • Security and Privacy: Use OAuth 2.0 and SMART on FHIR protocols for secure, patient-consented access.

  • Validation: Always validate data against the FHIR schema to maintain consistency and reliability.

AI FHIR Convertor

The AI FHIR Convertor

Healthcare systems generate massive amounts of JSON-based data from EHRs, APIs, and apps. Converting this data into FHIR format ensures seamless interoperability and compliance with global standards.

Most traditional tools are rule-based and format-limited, but our AI-driven FHIR converter automatically performs FHIR mapping from any JSON structure with no pre-processing required. They typically handle only a few predefined data standards such as HL7 v2, CDA, or CSV and require the input data to strictly follow a specific schema. This means that if your organization’s data doesn’t match those rigid formats, you need to spend significant time reshaping it before conversion.

Our AI-Powered FHIR Converter, available at converter.fhir.whitefox.cloud, takes a completely different approach. Instead of restricting you to specific legacy formats, it uses artificial intelligence to understand any JSON-based data structure, whether it comes from a legacy EHR, a custom application, or a third-party API, and intelligently map it to FHIR-compliant resources.

Key Innovation: Accepts Any Legacy Data Structure

Unlike conventional converters that require data in a specific syntax (like HL7 v2 messages), our converter which won the HL7 Interoperability Leadership Award at Global AI Challenge, will:

  • Accept any JSON or custom object structure, no matter how your legacy data is organized.

  • Use AI to analyze field names, types, and relationships, then match them automatically to the correct FHIR elements (e.g., mapping fullName to Patient.name, bp_value to Observation.valueQuantity).

  • Support multiple programming languages, generating ready-to-use conversion functions (in TypeScript, Python, C# or Java) that you can integrate directly into your system for ongoing transformations.

This means your organization doesn’t have to rebuild or normalize legacy datasets before integrating them with FHIR, the AI converter adapts to you.

Feature

AI-Powered FHIR Converter

Legacy / Traditional FHIR Converters

Input Data Support

Accepts any JSON or custom data structure — works with legacy systems, proprietary APIs, or flat data.

Limited to specific predefined formats (e.g., HL7 v2, CDA, or CSV).

AI-Driven Mapping

Uses AI to automatically detect field names, types, and relationships, mapping them intelligently to FHIR elements.

Requires manual configuration or static mapping files — complex and error-prone.

Programming Language Support

Generates conversion functions in multiple languages (TypeScript, Python, C#, Java) for seamless integration.

Usually provides only static output (e.g., a JSON or XML file) without reusable code.

FHIR Validation

Built-in real-time validation via integrated FHIR HAPI Server, ensuring compliant, ready-to-use resources.

Often lacks automated validation — requires external validation tools or manual QA.

Flexibility

Automatically adapts to any legacy schema — no data restructuring required.

Rigid input structure — requires data to be pre-formatted before conversion.

Ease of Use

Simple web-based UI — just upload data, select resource type, and click Convert.

Complex setup — often requires command-line tools or configuration scripts.

Continuous FHIR Validation

 Data integrity is central to our design. Each resource is rigorously validated using Whitefox public FHIR server. Every converted FHIR resource is automatically:

  • Validated against official FHIR schemas to ensure full compliance.

  • Checked through our FHIR server, confirming that the JSON output meets the structural and semantic rules of FHIR and the chosen Implementation Guide.

  • Delivered only after successful validation, ensuring the data you receive is fully compliant and ready for use in any FHIR-enabled environment.

Why This Matters

This automation accelerates interoperability and ensures reliable data transformation between old and new healthcare systems. By removing the dependency on rigid input formats and enabling AI-driven schema mapping, the converter:

  • Save weeks of mapping: Eliminates pre-processing overhead and there is no need to manually reformat or map data fields.

  • Accelerates interoperability: instantly turns any existing dataset into standardized, validated FHIR resources

  • Bridges legacy and modern systems: integrate older databases, APIs, or JSON payloads directly into FHIR-based workflows.

  • Generate reusable conversion code:  Empowers developers by using the generated conversion code to extend automation and maintaining long-term data compatibility.

Example in Action

A healthcare analytics company has a proprietary JSON schema for patient encounters. Traditional tools can’t process it because it’s not HL7 v2.

With our converter, they simply upload the JSON structure, select Encounter as the FHIR resource, and click Convert.
The AI instantly generates:

  • FHIR resource json output,

  • a conversion function mapping their fields to FHIR, and

  • a validated Encounter resource.

The result is not just a converted file, but a reusable transformation function they can call programmatically every time new data arrives.

How it Works (Step-by-Step)

  1. A FHIR resource is selected in the FHIR-converter.

  2. The input field is automatically populated with a sample JSON object for the selected resource type.

  3. The sample JSON may be replaced with a custom JSON object if required.

  4. A target programming language is chosen.

  5. The Convert button is clicked.

  6. The value from the input field is placed into a special prompt and will be sent to the GPT-4o assistant model.

  7. Each field in the provided JSON object is semantically interpreted by the assistant.

  8. A conversion function (in the chosen language) is generated by the assistant to convert json to FHIR valid format.

  9. The provided input is processed through the generated FHIR-converter function.

  10. The result is checked with our internal FHIR server for validation.

  11. The resulting FHIR output is populated into the designated output field for the user.


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Simplify Your FHIR Integration with Our Free Tools

FHIR Data Converter

Effortlessly transform and map custom data to FHIR standard formats.

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FHIR Test Server

Test, validate, and refine FHIR implementations securely online.

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Healthcare App Development & FHIR Services

From planning to integration and maintenance,
we deliver
healthcare app development and FHIR services
that work seamlessly together.

Frequently Asked Questions

FHIR (Fast Healthcare Interoperability Resources) is an open standard developed by HL7 International that enables healthcare systems to exchange data in a consistent, structured, and secure manner. It defines modular data units called resources (such as Patient, Observation, or Encounter) that represent common healthcare entities.

Earlier standards such as HL7 v2, HL7 v3, and CDA were crucial in healthcare data exchange but had limitations:

- HL7 v2 was easy to implement but lacked semantic consistency across vendors.

- HL7 v3 introduced more structure but was complex and difficult to adopt.

- CDA (Clinical Document Architecture) standardized document exchange but was document-centric and not ideal for granular data sharing.

FHIR evolved to address these issues by combining HL7’s rich data modeling with modern web technologies like RESTful APIs, JSON, and XML, making it both flexible and developer-friendly.

While the FHIR base specification provides global interoperability, every country or region has unique healthcare workflows and regulations.

To support this, FHIR Cores (Implementation Guides) define regional extensions and constraints on the base FHIR model:

- US Core – Used in the United States, aligned with ONC and USCDI standards.

- AU Core – Tailored to Australia’s My Health Record and privacy frameworks.

- UK Core – Developed for the NHS and UK-specific interoperability models.

These profiles ensure that FHIR remains globally consistent but locally adaptable by enabling compliance with regional healthcare systems.

FHIR uses RESTful APIs, similar to modern web applications, for data exchange.

Each FHIR resource can be created, read, updated, or deleted using standard HTTP operations (GET, POST, PUT, PATCH, DELETE).

Unlike traditional converters that only accept structured input formats like HL7 v2 or CDA, our AI-Powered FHIR Converter:

- Accepts any JSON-based or legacy data structure, regardless of its schema.

- Uses AI-driven field mapping to automatically understand and match data to appropriate FHIR elements.

- Generates conversion functions in multiple programming languages (TypeScript, Python, C#, Java) for direct use in your system.

- Validates every output through an integrated Whitefox FHIR Server, ensuring strict compliance before presenting results.

This makes it a universal and intelligent conversion solution, ideal for organizations with diverse data sources or legacy systems.

Currently the converter supports AU Core Profile and UK core and US core are under development and will be able in the future.

Each FHIR JSON output is validated automatically using the Whitefox FHIR Serve.

The validation process checks:

- Resource structure and required elements

- Data types and constraints

- Compliance with selected FHIR Core and Implementation Guide

Only successfully validated data is displayed or made available for download by ensuring reliability and compliance with international standards.

Absolutely. The converter provides ready-to-use conversion functions that can be embedded directly into your applications or APIs.

You can use them:

- As part of your real-time data ingestion pipeline,

- For bulk data transformation, or

- To maintain ongoing synchronization between legacy systems and your FHIR server.

- Efficiency – Automates data mapping and validation, saving weeks of manual effort.

- Accuracy – Reduces human error through AI-driven schema understanding.

- Flexibility – Works with any legacy JSON or custom format.

- Compliance – Ensures conformance with global and regional FHIR standards.

- Developer-Friendly – Generates reusable conversion functions for multiple programming languages.

You can access the converter directly at:

👉 https://converter.fhir.whitefox.cloud/

Simply:

1. Choose your FHIR resource and core profile.

2. Upload or paste your legacy JSON data.

3. Generate and review the AI-created conversion function.

4. Validate the output and download your FHIR-compliant JSON file.

The tool is completely web-based, intuitive, and doesn’t require installation.

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