How to Convert Between JSON CSV YAML XML and Excel

Developers constantly need to move data between formats. APIs return JSON. Analysts want Excel. DevOps configs are YAML. Legacy systems need XML. This guide covers every major data format conversion with working Python code and a free no-code option.

The five formats every developer needs

• JSON — default for APIs, JavaScript applications, NoSQL databases
• CSV — spreadsheets, database imports, data exchange
• YAML — configuration files, Kubernetes, Docker Compose, CI/CD
• XML — enterprise systems, SOAP APIs, RSS feeds, Office documents
• Excel (.xlsx) — business reporting, analyst workflows, data sharing

JSON to CSV

import json, csv

with open('data.json') as f:
    data = json.load(f)

with open('output.csv', 'w', newline='') as f:
    writer = csv.DictWriter(f, fieldnames=data[0].keys())
    writer.writeheader()
    writer.writerows(data)
print("JSON → CSV done")

CSV to JSON

import csv, json

with open('data.csv') as f:
    rows = list(csv.DictReader(f))

with open('output.json', 'w') as f:
    json.dump(rows, f, indent=2, ensure_ascii=False)
print(f"CSV → JSON: {len(rows)} records")

JSON to YAML

import json, yaml

with open('config.json') as f:
    data = json.load(f)

with open('config.yaml', 'w') as f:
    yaml.dump(data, f, allow_unicode=True,
              default_flow_style=False, sort_keys=False)
print("JSON → YAML done")

YAML to JSON

import yaml, json

with open('config.yaml') as f:
    data = yaml.safe_load(f)

with open('config.json', 'w') as f:
    json.dump(data, f, indent=2, ensure_ascii=False)
print("YAML → JSON done")

JSON to Excel

import pandas as pd

df = pd.read_json('data.json')
df.to_excel('output.xlsx', index=False, engine='openpyxl')
print(f"JSON → Excel: {df.shape[0]} rows, {df.shape[1]} columns")

Excel to CSV

import pandas as pd

df = pd.read_excel('data.xlsx', engine='openpyxl')
df.to_csv('output.csv', index=False)
print(f"Excel → CSV: {len(df)} rows")

XML to JSON

import xml.etree.ElementTree as ET
import json

def xml_to_dict(element):
    result = {}
    for child in element:
        child_data = xml_to_dict(child)
        if child.tag in result:
            if not isinstance(result[child.tag], list):
                result[child.tag] = [result[child.tag]]
            result[child.tag].append(child_data)
        else:
            result[child.tag] = child_data
    if element.text and element.text.strip():
        return element.text.strip()
    return result or element.text

tree = ET.parse('data.xml')
root = tree.getroot()
data = {root.tag: xml_to_dict(root)}

with open('output.json', 'w') as f:
    json.dump(data, f, indent=2)
print("XML → JSON done")

Choosing the right format

• Sharing with developers → JSON
• Sharing with analysts or business teams → Excel or CSV
• Configuration files → YAML (more readable) or JSON (more strict)
• Enterprise system integration → XML
• Database imports → CSV
• API payloads → JSON (minified)

Always validate data after conversion — especially when going from a typed format (Excel, JSON) to a less-typed one (CSV), and back again. Type information can be lost in the round trip.