OpenAI's omni-era workhorse — text and image in, text out, with a cached-input rate that halves the cost of repeated context.

Key specifications

Intelligence
77.5
Capability
46.8
Context window
128K
Max output
16.4K
Output speed
110 t/s
Latency (TTFT)
0.42s
Input $/1M
$2.50
Output $/1M
$10.00
License
Proprietary
Architecture
Transformer

Inputs and outputs

Recorded modality support shows what this model can accept and produce. An undocumented modality is shown as unknown rather than assumed to be unsupported.

Accepts

  • Text input
  • Image input
  • Audio input

Produces

  • Text output

Capabilities

Function callingVisionAudioStreamingJSON modeFine-tuning

What is GPT-4o?

The name promises more than the API delivers, and that is the first thing worth clearing up.

GPT-4o was introduced as OpenAI's omni-era model, and the demos showed voice and vision working together in real time. Through the API you get text and image input, and text output. No generated speech, no generated images. If you budgeted for a single model to handle a voice product end to end, budget again.

What you do get is a dependable general-purpose model with one genuinely clever pricing feature.

Caching is the reason to read the invoice

GPT-4o runs about $2.50 per million input tokens and $10.00 per million output tokens. Cached input drops to roughly $1.25 per million — half price.

That discount is not a rounding detail; it changes which architectures make sense. Any design that resends a stable prefix on every call — a long system prompt, a product catalogue, a policy document, a fixed few-shot block — pays half for that portion once it is cached. Structure prompts so the stable material sits at the front and the variable part at the end, and the saving arrives without changing a line of application logic.

Get the order backwards and you pay full price for the same tokens. It is the cheapest optimisation available here and the one most often missed.

Where its age shows

The knowledge cutoff is October 2023.

Measured against today that is a long silence. Anything released, renamed, repriced or deprecated since then is invisible to the model unless you put it in the prompt yourself. For a support assistant answering questions about your own product that hardly matters, because your documentation is in context anyway. For anything that reasons about the current state of the world, it matters a great deal, and retrieval stops being optional.

Context is 128,000 tokens. Respectable when it launched, ordinary now that million-token windows are widely available.

What it is still good at

Output ceiling is 16,384 tokens — double what several contemporaries allowed, and enough for a substantial file or a long structured response in one pass.

It calls tools reliably, it handles images without a separate vision pipeline, and it is probably the most thoroughly documented model in production anywhere. When something behaves oddly at two in the morning, someone has already written up the fix. That is worth more than a benchmark point.

Specifications

Field Value
Provider OpenAI
Context window 128,000 tokens
Maximum output 16,384 tokens
Knowledge cutoff October 2023
Input text, image
Output text
Tool calling Supported
Reasoning mode Not supported
Indicative pricing $2.50 in / $1.25 cached in / $10.00 out per million
Released 13 May 2024

Pricing and availability change; confirm against your own account before you plan a budget around them.

See how it stands against newer options in the AI model directory, or read Gemini 2.5 Flash if the 128K window is what you are trying to escape.

How to evaluate GPT-4o

Use the recorded facts as a shortlist, then validate the model against representative inputs and production constraints.

Workload fit

GPT-4o is categorized for Audio-text-to-text, Automatic speech recognition, Image-text-to-text, Image-to-text, Text generation, Text-to-text AI models. Its current record accepts text, image, audio and produces text. Confirm file formats, preprocessing, and provider-specific request schemas before implementation.

Capacity and cost

The directory records 128K context and 16.4K maximum output. Listed token prices are $2.50 input and $10.00 output per 1M tokens. Treat missing values as unknown and recheck current commercial terms.

Operational behavior

Recorded output speed is 110 t/s and time to first token is 0.42s. Hosting route, region, prompt length, concurrency, and provider load can materially change both measurements.

Evidence boundary

This page separates sourced model facts from incomplete fields. Benchmark evidence is displayed only when its source is linked and verified. Before choosing GPT-4o, test task quality, tool reliability, safety behavior, data controls, rate limits, and total cost on the exact route you intend to use.

Strengths

  • + Cached input at half the standard rate rewards workloads that resend the same context
  • + 16,384-token output is double what its contemporaries offered, so fewer stitched responses
  • + Reads images as well as text, which covers screenshots, diagrams and scanned documents
  • + Enormously well documented — two years of community patterns, wrappers and evaluation work

Limitations

  • October 2023 knowledge cutoff is now years stale; anything recent needs your own retrieval
  • 128K context is modest against the million-token windows now common
  • No reasoning mode — it answers rather than deliberating
  • The 'omni' name oversells the API surface: text and image in, text only out

Benchmark results

Each score below comes from a published result we could trace back to its source. Read them as evidence about the specific task a benchmark measures — a model that leads on one can easily trail on another.

No benchmark results recorded for this model yet. Add them with a source link and this section appears on the live page.

Frequently asked questions

GPT-4o is a OpenAI model in SyncDev’s directory. Use the linked primary source to confirm current product details.

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