Resize, Convert SVG & Generate Favicons Offline — WordsByEkta🌿
Stop Uploading Your Images to Random Websites. Resize, Convert, Compress & Even Generate SVG or ICO Files Yourself.
You need to resize an image. Maybe it's a blog banner, a thumbnail, a logo, a product photo. So you open a browser tab, find a site, upload the image, wait, download the result, and hope it didn't destroy the quality or bury you in ads.
Then next week you do it again.
I built a small Python script that does all of this locally — resize to any dimension, convert between PNG and JPG, compress under a file size limit — without uploading a single file anywhere.
Every time you upload an image to a free online tool, you are handing your file to a server you know nothing about. For personal photos, client work, or anything branded — that's a risk you're taking silently.
Resize, convert, compress. No uploads. No ads. No limits.
What this script does
- Resize any image to any width and height you choose
- Convert PNG to JPG or JPG to PNG automatically
- Accept PNG, JPG, JPEG, WEBP and most common formats
- Auto-compress only if the file exceeds your size limit
- Keep the highest possible quality throughout
- Works for any use case — blogs, social media, apps, client work, personal projects
- Generate favicon.ico files for apps and websites
- Convert SVG to PNG, JPG or ICO locally
- Basic PNG/JPG to SVG tracing for simple logos and icons
- Save converted files automatically beside the original image
One-time setup
You need Python installed — free from python.org. Then run this once in your terminal or command prompt:
terminal
pip install pillow opencv-python numpy cairosvg
That's it. Never again.
Important for SVG & ICO support on Windows
SVG conversion on Windows needs the GTK/Cairo runtime installed once. Without it, normal PNG/JPG resizing still works — but SVG to PNG/JPG/ICO conversion will fail.
Install the 64-bit GTK Runtime and keep the PATH option checked during installation.
Official download: GTK Runtime Win64 Releases
After installation, restart your terminal or command prompt once.
If SVG conversion fails even after installation, completely close and reopen your terminal once.
The script — copy, save, run
Paste this into a file called image_resizer.py and keep it anywhere on your machine.
image_resizer.py
from PIL import Image
import os
import cv2
import cairosvg
import numpy as np
import re
input_file = input(
"Enter input image file name/path: "
).strip().strip('"')
width_input = input(
"Enter output width (blank = original): "
).strip()
height_input = input(
"Enter output height (blank = original): "
).strip()
width = int(width_input) if width_input else None
height = int(height_input) if height_input else None
output_format = input(
"Output format? png, jpg, ico or svg: "
).strip().lower()
if output_format in ["jpg", "jpeg"]:
save_format = "JPEG"
elif output_format == "ico":
save_format = "ICO"
elif output_format == "svg":
save_format = "SVG"
else:
save_format = "PNG"
limit_input = input("Size limit? Examples: 100kb, 0.1mb, blank = no limit: ").strip().lower()
size_limit_bytes = None
if limit_input:
if limit_input.endswith("kb"):
size_limit_bytes = float(limit_input.replace("kb", "").strip()) * 1024
elif limit_input.endswith("mb"):
size_limit_bytes = float(limit_input.replace("mb", "").strip()) * 1024 * 1024
else:
# default to KB if only number is entered
size_limit_bytes = float(limit_input) * 1024
input_folder = os.path.dirname(
os.path.abspath(input_file)
)
base_name = os.path.splitext(
os.path.basename(input_file)
)[0]
if input_file.lower().endswith(".svg"):
temp_png = "__temp_png__.png"
cairosvg.svg2png(
url=input_file,
write_to=temp_png,
)
img = Image.open(temp_png)
else:
img = Image.open(input_file)
if width is None:
width = img.width
if height is None:
height = img.height
if output_format in ["jpg", "jpeg"]:
output_file = f"{base_name}_{width}x{height}.jpg"
save_format = "JPEG"
elif output_format == "ico":
output_file = f"{base_name}_{width}x{height}.ico"
save_format = "ICO"
elif output_format == "svg":
output_file = f"{base_name}_{width}x{height}.svg"
save_format = "SVG"
else:
output_file = f"{base_name}_{width}x{height}.png"
save_format = "PNG"
output_file = os.path.join(
input_folder,
output_file
)
if save_format == "SVG":
if input_file.lower().endswith(".svg"):
with open(input_file, "r", encoding="utf-8") as f:
svg_content = f.read()
if 'width="' in svg_content:
svg_content = re.sub(
r'width="[^"]*"',
f'width="{width}"',
svg_content
)
else:
svg_content = svg_content.replace(
" 300:
print("This image is too complex for clean SVG conversion.")
print("Use PNG/JPG instead, or trace manually in Inkscape.")
exit()
paths = []
for contour in contours:
if cv2.contourArea(contour) < 5:
continue
points = contour.squeeze()
if len(points.shape) != 2:
continue
d = f"M {points[0][0]} {points[0][1]} "
for point in points[1:]:
d += f"L {point[0]} {point[1]} "
d += "Z"
paths.append(f'
How to use it
- Place your image in the same folder as the script (or anywhere — just type the full path. To copy image path: right click → Copy as path)
- Double-click the script or run python image_resizer.py in terminal
- Enter the filename — e.g. banner.png
- Enter your target width and height in pixels
- Choose png, jpg, ico or svg as output
- Optionally enter a size limit like 1 for 1 MB — or just press Enter to skip
Example run
example
Enter image filename (e.g. photo.png): banner.png
Output width (px): 1200
Output height (px): 630
Output format? png, jpg, ico or svg: ico
Size limit in MB? Press Enter to skip: 1
Done!
Original size : 3420.18 KB
Saved as : banner_1200x630.ico
Final size : 187.42 KB
The script always starts at maximum quality. It only reduces further if the file is still above your chosen size limit — so you always get the best result possible.
favicon example
Enter input image file name/path: logo.svg
Output width (px): 256
Output height (px): 256
Output format? png, jpg, ico or svg: ico
Done!
Output file: logo_256x256.ico
SVG & ICO support
- ICO: Useful for website favicons and app icons
- SVG: Best for logos, icons and scalable graphics
- The script can convert SVG files into PNG, JPG or ICO locally
- The script can also attempt basic PNG/JPG to SVG tracing for simple shapes
PNG/JPG to SVG tracing works best for logos, icons and flat graphics. Complex photographs usually do not convert into clean SVG files automatically.
PNG vs JPG — which one to pick
- PNG: Best for logos, icons, anything with transparency or sharp edges
- JPG: Best for photos, banners, gradients, large images where file size matters
- Converting a PNG to JPG alone often cuts the file size dramatically without visible quality loss
- If a PNG is too large and you need it under a limit, JPG is almost always the answer
Why local beats online every time
Online image tools are everywhere and most of them work — technically. But they come with things you didn't sign up for: ads, upload limits, watermarks, quality loss you can't control, and files sitting on someone else's server. You also avoid uploading logos, app icons, branding files or client assets to random online converters.
This script has none of that. It runs in seconds, keeps your files exactly where they are, and gives you full control over dimensions, format, and compression. You don't need to understand the code. You just need to run it.
Sometimes the best tool is a small script you fully own — no account, no limit, no ads, no upload.
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Created by WordsByEkta🌿 — documenting real creator experiments in blogging, SEO, KDP publishing, AI-assisted app building, and technical troubleshooting.
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