Reviews

GPT-4o Review: OpenAI's Omni Model Explained (2025)

June 14, 2025 3 min read

GPT-4o Review: OpenAI’s Omni Model

GPT-4o (the “o” is for “omni”) is OpenAI’s multimodal flagship. It sees, hears, and speaks—all in one model.

Here’s everything you need to know.

What Makes GPT-4o Different

True Multimodal

Previous models patched together different systems. GPT-4o is natively multimodal:

  • Text in, text out
  • Images in, text out
  • Audio in, audio out
  • Any combination

This isn’t just “GPT-4 with plugins.” It’s a single model handling everything.

Speed

GPT-4o responds in real-time for voice conversations. Average audio response time: 320 milliseconds. That’s human-like conversation speed.

Cost

50% cheaper than GPT-4 Turbo via API. This matters for developers.

Free Tier Access

Unlike GPT-4, GPT-4o is available on the free ChatGPT tier. Limited, but available.

Features Deep Dive

Vision

GPT-4o analyzes images effectively:

  • Read text in images
  • Describe visual content
  • Solve visual problems
  • Analyze charts and graphs

Real use cases: Reading receipts, understanding diagrams, solving math written on paper.

Voice Mode

The advanced voice mode is impressive:

  • Natural conversation flow
  • Emotional expression
  • Interruption handling
  • Multiple voices available

Limitation: Rolling out gradually. Not available to all users.

Real-Time API

For developers: stream audio in and out in real-time. Build voice assistants, phone agents, interactive experiences.

Performance

Benchmarks

GPT-4o matches or exceeds GPT-4 Turbo on most benchmarks while being faster and cheaper.

BenchmarkGPT-4oGPT-4 Turbo
MMLU88.7%86.4%
HumanEval90.2%85.4%
SpeedFasterSlower
CostLowerHigher

Real-World Quality

In our testing:

  • Writing: Comparable to GPT-4 Turbo
  • Coding: Slightly improved
  • Reasoning: Similar
  • Multimodal: Significantly better

Pricing

API

ModelInput (per 1M tokens)Output (per 1M tokens)
GPT-4o$5.00$15.00
GPT-4 Turbo$10.00$30.00

50% cheaper across the board.

ChatGPT

  • Free: Limited GPT-4o access
  • Plus ($20/month): More GPT-4o, priority access
  • Team ($25/user/month): Higher limits, team features

Versus Competition

vs Claude 3.5 Sonnet

AspectGPT-4oClaude 3.5 Sonnet
WritingGoodBetter
CodingBetterGood
VoiceYesNo
VisionYesYes
Context128K200K

vs Gemini Pro

AspectGPT-4oGemini Pro
QualityBetterGood
SpeedFastVery fast
IntegrationBroadGoogle-focused
Free accessLimitedGenerous

Best Use Cases

Voice Applications

The real-time audio makes GPT-4o ideal for:

  • Voice assistants
  • Language tutoring
  • Customer service bots
  • Accessibility tools

Visual Analysis

Strong vision capabilities suit:

  • Document processing
  • Visual Q&A
  • Educational tools
  • Creative assistance

General Use

For most ChatGPT users, GPT-4o is now the default. It’s fast, capable, and handles most tasks well.

Limitations

Knowledge Cutoff

Still has a training data cutoff. Not real-time information (without browsing features).

Hallucinations

Still makes things up occasionally. Verify important information.

Voice Availability

Advanced voice features rolling out slowly. Not everyone has access.

Reasoning Limits

For very complex reasoning, OpenAI’s o1 models are better (but slower).

Who Should Use GPT-4o

Everyone using ChatGPT. It’s the default for good reason.

Developers: Cheaper and faster than GPT-4 Turbo. Migrate.

Voice applications: The real-time audio API opens new possibilities.

Our Verdict

GPT-4o represents AI becoming more natural and accessible. Faster, cheaper, and more capable than its predecessor.

Strengths:

  • Real-time voice
  • Strong multimodal
  • Cost-effective
  • Fast responses

Weaknesses:

  • Writing slightly below Claude
  • Still hallucinates
  • Gradual feature rollout

Rating: 9/10

It’s not revolutionary over GPT-4 Turbo, but it’s better in almost every way. The standard just moved up.


GPT-4o makes advanced AI more accessible than ever. That’s good for everyone.

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