Which AI API should I choose if I need image understanding, text extraction, and low latency in one workflow?

If you need image understanding + text extraction (OCR) + low latency in one workflow, the best choice is usually a multimodal vision-capable LLM API that can process the image directly and return both semantic understanding and extracted text in a single call.

Best overall fit

OpenAI GPT-4o / GPT-4.1 (vision-capable)

• Handles image understanding very well
• Can do OCR-like text extraction
• Generally low latency relative to heavier multimodal systems
• Good for a single-step workflow where you want captioning, document reading, entity extraction, and reasoning together

Strong alternatives

Anthropic Claude 3.5 Sonnet (vision)

• Very strong at document/image interpretation and structured extraction
• Good for forms, screenshots, and mixed text/image understanding
• Latency can be competitive, though exact performance depends on payload size and deployment

Google Gemini 1.5 Flash

• Especially good if latency and cost are top priorities
• Strong multimodal support and long context
• Often a good option for fast document/image pipelines

If OCR accuracy is the top priority

If you need best-in-class text extraction from scanned documents, receipts, or photos, a dedicated OCR service may still be better:

• Google Cloud Vision OCR
• AWS Textract
• Azure AI Document Intelligence

Then you can pass the extracted text to an LLM for interpretation.
But if you want one API call, use a multimodal LLM.

Practical recommendation

• Single API, balanced quality + speed: GPT-4o / GPT-4.1
• Fastest/cheapest multimodal: Gemini 1.5 Flash
• Best doc/image reasoning and extraction: Claude 3.5 Sonnet
• Highest OCR accuracy for documents: Textract / Document AI / Vision OCR + LLM

My short answer

If you want one workflow that does all three well, start with OpenAI GPT-4o or GPT-4.1.
If you want, I can also give you a decision table comparing OpenAI, Anthropic, and Google for latency, OCR quality, and cost.