Free Topaz Gigapixel Alternative: AI Image Upscaler API

A production REST API for AI image upscaling — the developer-grade topaz gigapixel alternative free of a desktop license. One HTTP call upscales any photo or product image 2–16× with detail recovery, sharp edges, and clean output. $0.009 per image — significantly lower-priced than Topaz Gigapixel, Vance.ai, Let's Enhance, and Upscale.media. 5,000 free credits (24-hour trial), no credit card.

Quick start — upscale an image in one API call

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 "image=@photo.jpg" \
  -F "scale=4"
# Response: {"id": "uuid", "status": "queued", "credits_used": 9}

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

pip install pixelapi
---
from pixelapi import PixelAPI

client = PixelAPI(api_key="YOUR_API_KEY")
result = client.upscale(image="photo.jpg", scale=4)
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", 4)
if err != nil { panic(err) }
result.Save("photo_4x.png")

Upscale parameters at a glance

Pricing — free Topaz Gigapixel alternative vs rivals

Pricing verified from each rival's public pricing page, October 2026: developer.topazlabs.com, vanceai.com/pricing, letsenhance.io/pricing, upscale.media/pricing. PixelAPI price based on canonical billing (9 credits × $0.001/credit).

What you get back

Common use cases for AI image upscaling

The Image Upscaler API covers these production workflows. Each links to a related guide:

Integrations

The Image Upscaler API integrates with popular platforms via the PixelAPI SDK and webhook events:

Comparison vs alternatives — free Topaz Gigapixel alternative

Rate limits & error handling

20 requests/minute on the free trial, 60 on Starter, 120 on Pro, and 300 on Scale — with 3/10/20/50 concurrent jobs respectively. Exceeding the limit returns HTTP 429 with a Retry-After header. For large batch workloads, use the concurrent jobs cap to parallelize throughput rather than hammering rate limits.

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

# Batch: submit N jobs, collect results
import asyncio
from pixelapi.async_client import AsyncPixelAPI

async def batch_upscale(paths):
    client = AsyncPixelAPI(api_key="...")
    jobs = await asyncio.gather(*[client.upscale(image=p, scale=4) for p in paths])
    return jobs

Common error codes: 400 invalid parameters or unsupported file, 402 insufficient credits, 413 image exceeds 20 MB, 429 rate limit hit. All errors return JSON with a detail field. Credits are never charged for jobs that fail input validation or produce blank output — failures trigger an automatic refund.

Frequently asked questions