Do I need an SDK or is it a raw REST API?

It's a raw REST API. No SDK required. Any language that can make HTTP requests — Python, JavaScript, PHP, Ruby, Go, cURL — can call the Alt Magic API directly with no additional libraries.

How are credits deducted — per request or per image?

Credits are deducted per request, and each request generates alt text for one image. A request that fails due to an invalid URL or insufficient credits does not consume a credit.

What is the average response time?

Typical response time is 800ms–2s depending on image size and model load. The API uses Gemini as the primary model with OpenAI as automatic fallback for maximum uptime.

REST APIv1

Alt Text API — Generate AI Alt Text for Any Image, Programmatically

A single POST request. Any image URL. Alt text back in milliseconds. 200+ languages. Gemini + OpenAI dual-model reliability.

Get API Key Free View API Docs

REST API

200+ Languages

100 req/min

Gemini + OpenAI Fallback

JSON Response

No SDK Required

Request

# cURL example
curl -X POST "https://api.altmagic.pro/v1/generate-alt-text-api" \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "image_url": "https://yoursite.com/product.jpg",
    "seo_keywords": "leather sofa, living room",
    "language_code": "en"
  }'

Response · 200 OK · ~1.2s

{
  "altText": "A brown leather sofa in a bright
          modern living room with natural light",
  "CreditsAvailable": 49
}

API Capabilities

What the Alt Magic API Does

Everything you need to add intelligent, multilingual, SEO-optimized alt text to any image pipeline.

Core

Generate Alt Text for Any Publicly Accessible Image URL

Pass any image URL via image_url. The API handles JPG, PNG, WebP, AVIF, GIF, and SVG. No image upload required — just the URL.

SEO-Keyword Injection via seo_keywords Parameter

Pass your target keywords and the AI will naturally embed them into the generated alt text — without stuffing. Ideal for content pipelines that already have keyword data per image.

Context-Aware Generation with blog_title

Provide the surrounding context (blog post title, page name, product title) and the API generates alt text that matches the editorial intent of the page — not just what's visually in the image.

200+ Languages via language_code

Specify any BCP 47 language code and receive alt text in that language. English, Spanish, French, German, Japanese, Arabic, Hindi, Chinese (Simplified/Traditional), Portuguese, and 190+ more.

Reliable

Gemini + OpenAI Dual-Model Fallback

The API automatically uses Gemini as the primary model and falls back to OpenAI if needed — so you get maximum uptime and reliability without managing model routing yourself.

API Key Authentication + 100 Req/Min Rate Limit

Authenticate via the x-api-key header. Standard rate limit is 100 requests per minute, suitable for most automation pipelines and batch processing workflows.

Use Cases

Who Uses the Alt Magic API

From content agencies to headless CMS platforms — built for any image pipeline.

Content Agencies

Automate alt text for every image across 50+ client sites. Pipe image URLs through the API and push results back into your CMS via webhooks or scheduled jobs.

Headless CMS Platforms

Connect to Contentful, Sanity, or any custom CMS. Generate alt text at the time of asset upload and store it in the image metadata field automatically.

Ecommerce Platforms

Process new product image uploads in real-time or batch-process entire catalogs on demand. Pass product title as blog_title for ecommerce-accurate alt text.

Image CDNs / Media Libraries

Integrate at the point of upload into S3, Cloudflare Images, or any DAM system. Run alt text generation as part of your media processing pipeline.

Make.com / Zapier Automation

No-code workflows that trigger alt text generation on new image uploads from Google Drive, Dropbox, Airtable, or any connected source.

WordPress Developers

Build custom integrations or extend the Alt Magic plugin for bespoke multisite or enterprise WordPress setups using the same API the plugin uses.

Reference

API Parameters at a Glance

Full documentation at docs.altmagic.pro

Request Body (JSON)

Parameter	Required	Type	Description
`image_url`	Required	`String`	Publicly accessible URL of the image
`user_id`	Required	`String`	Your account email address
`seo_keywords`	Optional	`String`	Keywords to embed naturally in alt text
`blog_title`	Optional	`String`	Page/post/product title for context
`language_code`	Optional	`String`	BCP 47 language code (default: 'en')

Request Headers

Header	Required	Value
`x-api-key`	Required	Your API key from Alt Magic dashboard
`Content-Type`	Required	application/json

Error Handling

HTTP Status Codes

Code	Meaning	How to Fix
`200`	Success	Alt text returned in response body
`400`	Bad Request	Check required parameters (image_url, user_id)
`401`	Unauthorized	Verify your x-api-key header is correct
`403`	Forbidden	Insufficient credits — top up your account
`429`	Rate Limit Exceeded	Reduce to <100 requests per minute
`500`	Server Error	Retry with exponential backoff

No-Code

Use Without Writing Code

The same API, accessible through automation platforms.

Make.com Module

Build no-code alt text workflows. Trigger on file upload from Google Drive, Airtable, Dropbox, or any app.

View Make.com Integration

Zapier Integration

Trigger alt text generation on new image upload events from thousands of apps. Coming soon.

Coming Soon

WordPress Plugin

Uses the same API under the hood — zero configuration once connected. Install and forget.

WordPress Plugin Page

FAQ

Developer FAQ

One API key. Every image. Any platform.

Start with free credits. No SDK, no infrastructure, no setup. Just a POST request and alt text back in milliseconds.

Get Your Free API Key Read the Full API Docs

WordPress Plugin·Shopify App·Pricing