Usage¶

The core API is a single function, svg_to_bytes(), which renders SVG markup to PNG bytes.

Rendering pipeline¶

        flowchart LR
    A[svg_string] --> P{parse XML}
    B[svg_path] --> P
    P --> T{has <text>?}
    T -->|yes| F[load fonts]
    T -->|no| S[skip fonts]
    F --> R[build usvg Tree]
    S --> R
    R --> D{dimensions}
    D -->|width| W[scale width]
    D -->|height| H[scale height]
    D -->|width+height| WH[fixed size]
    D -->|zoom| Z[multiply]
    D -->|none| O[original]
    W --> X[render pixmap]
    H --> X
    WH --> X
    Z --> X
    O --> X
    X --> E[encode PNG]
    E --> Out[bytes]

Basic usage¶

import resvg_py

svg_string = """
<svg width="300" height="130" xmlns="http://www.w3.org/2000/svg">
    <rect width="200" height="100" x="10" y="10" rx="20" ry="20" fill="blue" />
</svg>
"""

png_bytes: bytes = resvg_py.svg_to_bytes(svg_string=svg_string)

Note

svg_to_bytes returns raw PNG bytes – not base64. Encode yourself if you need a data URI.

From a file¶

Pass a path instead of a string. .svgz (gzip-compressed) files are automatically detected and decompressed.

png_bytes = resvg_py.svg_to_bytes(svg_path="/path/to/image.svg")

Warning

If both svg_string and svg_path are provided, svg_string takes precedence. The path is only consulted when the string is empty or None.

Resize at render time¶

# fixed width and height
resvg_py.svg_to_bytes(svg_string=svg, width=800, height=600)

# width only -- height scales proportionally
resvg_py.svg_to_bytes(svg_string=svg, width=1920)

# height only -- width scales proportionally
resvg_py.svg_to_bytes(svg_string=svg, height=1080)

# zoom factor
resvg_py.svg_to_bytes(svg_string=svg, zoom=2)

Base64 data URI¶

import base64

png_bytes = resvg_py.svg_to_bytes(svg_string=svg)
b64 = base64.b64encode(png_bytes).decode("utf-8")
print(f"data:image/png;base64,{b64}")

Background color¶

resvg_py.svg_to_bytes(svg_string=svg, background="#f0f0f0")
resvg_py.svg_to_bytes(svg_string=svg, background="rgba(255,0,0,0.5)")

Tip

Any valid CSS color works – named colors, hex, rgb, hsl, all supported.