Clear Image Requests Start Before You Press Send

A chat API can receive more than typed messages. With a model that supports image input, your application can send a photograph, screenshot, or scanned page alongside a question. The important detail is that the picture must reach the API as image content, not merely as a filename mentioned in your text. A successful request pairs a readable image with clear instructions.

Image support depends on the selected model

Before preparing an upload, confirm that your chosen model accepts images through the endpoint you plan to use. A model that writes excellent text does not necessarily accept visual input. Even within one provider, supported image formats, size limits, and request structures can differ.

Check the current documentation for the model and API route, rather than assuming every chat endpoint behaves identically. An SDK can help assemble a request, but it cannot give an unsupported model the ability to inspect pictures.

The picture travels inside a structured message

Think of a multimodal chat message as an envelope containing separate pieces: one piece holds your instructions, while another identifies the image. Typing the name of a picture stored on your computer does not transfer that picture. Your application must supply its content through a supported mechanism.

Some APIs accept an image address that their servers can retrieve. Others accept image bytes encoded as text, often called base64, or a reference to a previously uploaded file. These approaches are not interchangeable everywhere. Follow the format required by your selected endpoint, including its rules for labeling the image type.

If you use a remotely hosted image, make sure the provider can actually retrieve it. A picture visible in your signed-in browser may still be inaccessible to an API server. Avoid making sensitive images public just to simplify retrieval.

Readable images produce more useful first answers

Start with a sharp image that shows the relevant details. Tiny lettering, glare, blur, and heavy compression can make interpretation unreliable. Cropping out irrelevant surroundings often helps, but preserve enough context for the task. A tightly cropped receipt total, for example, may omit the currency or the label explaining that number.

Ask for a specific result. Instead of requesting a general description of a dashboard screenshot, ask the model to identify visible error messages and explain their likely meaning. For document extraction, specify the fields you need and ask it to flag unreadable text rather than guess.

Several images need clear labels and boundaries

When sending multiple images, explain their relationship and identify them by order. State whether they are separate documents, consecutive pages, or different views of the same object. Request limits may apply to each image, the total request, or both.

Treat text inside pictures as material to analyze, not as trusted instructions. A screenshot can contain misleading directions just as a pasted document can. Your application should keep its actual task instructions separate from the image content.

Relay access still requires model-specific request checks

BestRelay publishes this guide as a quality-first API relay that forwards each request to the official model named in it, without substitution. Its coverage includes Claude, GPT, Gemini, DeepSeek, Kimi, GLM, Qwen, Grok, and more. That breadth does not make image support uniform across those families.

BestRelay works with Claude Code, Codex, Gemini CLI, and any OpenAI SDK; image handling still depends on the selected tool, model, and route. Create a BestRelay account when you are ready to try an image request.

Billing is pay-as-you-go, based on token counts reported by the provider, with cache reads and writes priced separately. Image processing can contribute to usage, so review reported consumption rather than judging cost from the length of your question. Members also earn a referral commission when people they invite top up.

A small test reveals most integration mistakes

Begin with one ordinary, non-sensitive image and a simple question. If the request fails, check model compatibility, image accessibility, file type, and size limits before adding more images. If the answer is weak, inspect readability and sharpen the instructions. Remove unnecessary personal details before sending anything, and verify consequential results against the original image.