How to Visualize JSON in Python: Graphs, Trees & Code

1. Programmatic Graph Visualization with NetworkX & Matplotlib

To generate an offline node graph from a JSON file in Python, you can recursively traverse the dictionary and build a directed graph (nx.DiGraph):

import json
import networkx as nx
import matplotlib.pyplot as plt

def build_graph(data, graph=None, parent=None, key="root"):
    if graph is None:
        graph = nx.DiGraph()
    node_id = f"{parent}.{key}" if parent else key
    graph.add_node(node_id, label=str(key))
    if parent:
        graph.add_edge(parent, node_id)
        
    if isinstance(data, dict):
        for k, v in data.items():
            build_graph(v, graph, node_id, k)
    elif isinstance(data, list):
        for i, item in enumerate(data):
            build_graph(item, graph, node_id, f"[{i}]")
    return graph

# Load and plot
with open("data.json") as f:
    payload = json.load(f)
G = build_graph(payload)
pos = nx.spring_layout(G)
nx.draw(G, pos, with_labels=True, node_color="#38bdf8", font_size=8)
plt.savefig("json_graph.png", dpi=300)

2. When to Use Python vs. an In-Browser Visualizer