Topaz Gigapixel Open Source Alternative: 4× AI Image Upscaler API

The leading topaz gigapixel open source alternative for developers. PixelAPI wraps Real-ESRGAN — the same open-source model that powers the best upscalers — in a production REST API with one HTTP call. Topaz Gigapixel is a proprietary desktop app at $149/year with no public API. PixelAPI is $0.01 per image, works server-side from any language, and ships 500 free credits with no credit card required.

Why developers switch from Topaz Gigapixel to PixelAPI

Topaz Gigapixel AI is a high-quality desktop application — but it has no public API. You cannot call it from a server, embed it in a pipeline, or process images programmatically without screen-automation hacks. PixelAPI solves that by exposing the same open-source upscaling model (Real-ESRGAN) as a clean REST endpoint you can call from any language or CI pipeline.

Quick start — one API call to upscale 4×

Sign up, copy your key from the dashboard, and POST your image. The endpoint returns a generation id; poll until status=completed, then download the upscaled PNG from output_url.

curl -X POST https://api.pixelapi.dev/v1/image/upscale \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -F "[email protected]" \
  -F "scale=4"
# Response: {"id": "uuid", "status": "queued", "credits_used": 10}

# Poll until completed
curl https://api.pixelapi.dev/v1/image/upscale/UUID \
  -H "Authorization: Bearer YOUR_API_KEY"
# Response: {"generation_id": "uuid", "status": "completed", "output_url": "https://..."}

pip install pixelapi
---
import time
from pixelapi import PixelAPI

client = PixelAPI(api_key="YOUR_API_KEY")
result = client.upscale(image="photo.jpg", scale=4)

while result.status != "completed":
    time.sleep(2)
    result = result.refresh()

result.save("photo_4x.png")  # upscaled PNG

npm install pixelapi
---
import { PixelAPI } from "pixelapi";

const client = new PixelAPI({ apiKey: process.env.PIXELAPI_KEY });
const result = await client.upscale({ image: "./photo.jpg", scale: 4 });
await result.save("photo_4x.png");  // upscaled PNG

composer require pixelapi/pixelapi
---
<?php
use PixelAPI\Client;

$client = new Client(getenv("PIXELAPI_KEY"));
$result = $client->upscale(["image" => "photo.jpg", "scale" => 4]);
file_put_contents("photo_4x.png", $result->getBody());

gem install pixelapi
---
require "pixelapi"

client = PixelAPI::Client.new(api_key: ENV["PIXELAPI_KEY"])
result = client.upscale(image: "photo.jpg", scale: 4)
File.binwrite("photo_4x.png", result.body)

go get github.com/pixelapi/pixelapi-go
---
import "github.com/pixelapi/pixelapi-go"

client := pixelapi.New("YOUR_API_KEY")
result, err := client.Upscale("photo.jpg", pixelapi.UpscaleOpts{Scale: 4})
if err != nil { panic(err) }
result.Save("photo_4x.png")

Pricing — vs Topaz Gigapixel and other upscalers

Topaz Gigapixel pricing verified from topazlabs.com/pricing May 2026. Other rival pricing is subscription or credit-based with opaque per-image costs — see each provider's pricing page for current rates. PixelAPI's per-image price is set at exactly half the cheapest comparable REST API rate per our pricing principle.

What you get back

Request parameters

Common workflows

The Image Upscaler API is the foundation for these production workflows. Each links to a setup guide:

More use-case guides: all industries →

Integrations & SDKs

Comparison vs alternatives

Rate limits & error handling

Default 60 requests/minute on the free tier, 600 requests/minute on paid tiers. Exceeding the limit returns HTTP 429 with a Retry-After header. Recommended: exponential backoff starting at 2 s, doubling on each retry up to 30 s. The Python and Node SDKs handle retries automatically.

# Python SDK auto-retries 429 with backoff
from pixelapi import PixelAPI
client = PixelAPI(api_key="...", max_retries=4)
result = client.upscale(image="bulk_photo.jpg", scale=4)  # auto-retries on 429

Credits are deducted on job submission. If the job fails for any reason, credits are auto-refunded — you never pay for a broken result. Failed jobs return status=failed with an error_message. Common errors:

Frequently asked questions