We Tested Grok 4, Claude, Gemini, GPT-4o: Which AI Should You Use In July 2025?

Choosing the right AI assistant in 2025 goes beyond brand hype — it comes down to what the model can actually do. Whether you’re coding, writing, solving complex problems, or just chatting, four AI models dominate the conversation: Grok 4, ChatGPT-4o, Claude Opus 4, and Gemini 2.5 Pro. Each excels in different areas — one leads in deep reasoning, another in natural conversation, and others in creativity or multimodal capabilities.

In the past year, AI development turned into an actual race. Each company released their answer to GPT-4o, which had over a year’s head start. Anthropic launched Claude Opus 4 in May 2025, Google DeepMind followed with Gemini 2.5 Pro in June, and xAI dropped Grok 4 in July.

All these LLMs were clearly aiming to challenge OpenAI’s lead — but each focused on different strengths. Anthropic doubled down on clarity, memory, and writing. Google went for scale and multimodal tools. xAI pushed hard on reasoning and benchmarks.

This article compares all four models across eight essential categories and finishes by helping you decide which one is the best fit for your needs — whether you’re a student, developer, creative, or an enterprise user.

General Knowledge & Conversation

AI models have become everyday companions, answering questions, explaining concepts, translating, and chatting. That’s why natural, accurate conversation is one of the most important metrics. We’re looking at how well each model understands questions, holds context, and handles multilingual interactions.

1st – GPT-4o still leads in natural interaction, especially for voice-based communication. OpenAI trained it end-to-end on text, audio, and images, allowing it to recognize tone, emotion, and background noise. With response times of around 232ms, it feels impressively human. Multilingual understanding is also top-tier, and it’s the most accessible model (free in ChatGPT, high limits for Plus users). While video support is planned, it’s not yet publicly available, but its current voice and vision performance is strong in fluidity.

2nd – Grok 4 is surprisingly conversational and witty, and often the most fun to talk to. It combines strong reasoning with personality, humor, and a human-like tone that makes it feel less like a tool and more like a quirky assistant, which was a touch directly from xAI’s owner Elon Musk. Grok now supports image input and voice, though while its audio experience isn’t as fast or polished as GPT-4o’s, it holds its own. For users who prefer lively banter over robotic politeness, Grok is a favorite.

3rd – Claude Opus 4 excels at calm, thoughtful conversation. It’s ideal for structured discussions, deep explanations, and analytical writing. Its memory helps maintain context and tone over extended chats. Claude also now supports voice conversations through its web interface, offering natural spoken interaction — though response times are slower and less fluid than GPT-4o.

4th – Gemini 2.5 Pro communicates well but tends to sound formal or technical. It does especially well when visuals are involved (like interpreting charts or screenshots), but in casual back-and-forth, it can feel less intuitive. That said, Google DeepMind designed Gemini with a focus on productivity-driven conversations and task-oriented interactions, less so for small talk or storytelling.

Coding & Software Development

The ability to generate and modify code is critical for developers — and a core test of practical AI usefulness. Here, we compare the models using metrics such as SWE-Bench (real GitHub issues), HumanEval (code generation), and hands-on capabilities across dev tools.

1st – Grok 4 is already redefining AI coding through its integration with tools like Cursor. This development environment allows Grok to assist with multi-file navigation, deep repository-level debugging, and intelligent refactoring — not just in theory, but in production today. Its strong reasoning engine and ability to understand project structure give it a major edge in real-world dev workflows. And with the Grok 4 Code variant on the horizon, it’s likely to further extend its lead in serious software development.

2nd – Claude Opus 4 excels in traditional coding benchmarks like SWE-Bench Verified (72.5%) and has demonstrated exceptional performance in long-running refactoring and planning tasks. Its extended reasoning mode helps it think step-by-step, making it an excellent assistant for large scale projects, especially in research or enterprise settings.

3rd – Gemini 2.5 Pro performs excellently in code editing (74% Aider benchmark) and app creation from visual prompts. It also scores a solid 63.8% on SWE-Bench Verified, making it ideal for prototyping and front-end development workflows. It’s especially convenient for developers already embedded in Google’s ecosystem. However, its reasoning depth and handling of large, complex codebases doesn’t yet match the top two models.

4th – GPT-4o scores an impressive 90.2% on HumanEval, which measures how well models generate correct code from clear, single-function prompts. It’s highly effective for small scale tasks and rapid iteration, but lacks the same depth as others when handling longer codebases or more ambiguous development tasks.

Math & Complex Reasoning

The true intelligence of an AI model shows when it needs to think like a human — solving multi-step problems, connecting knowledge across domains, and drawing conclusions. This category is based on benchmarks like Humanity’s Last Exam (HLE, a test of human-style reasoning across science, logic, and ethics), AIME (math olympiad problems), GPQA (graduate-level logic), and ARC-AGI-2, a test designed to evaluate the abstract reasoning and problem-solving capabilities of advanced AI systems.

1st – Grok 4 is unmatched in this category. It scored 50.7% on HLE with tools, 26.9% without tools, and 15.9% on ARC-AGI-2. Grok 4 is tools-native, meaning it was trained to use tools as part of its reasoning, not just bolted on after training. That gives it an edge in logic-heavy tasks that require calculation, interpretation, and multi-domain thinking.

2nd – Gemini 2.5 Pro posts excellent scores on AIME (86.7%) and GPQA (84%), solving tough quantitative problems. It also achieved a remarkable 21.64% on HLE, showing strength in complex reasoning, but scored just 4.9% on ARC-AGI-2 — a benchmark where Grok dominates. While strong in logic, its performance in general intelligence tasks still lags behind the leader.

3rd – Claude Opus 4 performs well in mainstream reasoning tests (75.5% AIME, 79.6% GPQA) and maintains focus over lengthy tasks. While Anthropic designed Claude to be a steady and capable model, it doesn’t push the boundaries of abstract reasoning like Grok or Gemini.

4th – GPT-4o scores highly on MGSM (90.5%, a benchmark of grade-school math problems) and DROP (83.4%, a challenging reading comprehension dataset). However, it lacks results in higher-order reasoning benchmarks like HLE or ARC, which leaves it a step behind in this category.

Long Documents & Context Handling

The ability to understand and process long documents is crucial for research, legal analysis, software engineering, and other workflows where AI must retain and refer back to large amounts of information. In this section, we’re comparing context window size, memory retention, and practical examples of complex usage.

1st – Gemini 2.5 Pro technically leads with its 1 million token context window, making it the undisputed winner in pure memory capacity. It can process books, large codebases, or cross-referenced research data without breaking a sweat. While its performance in extended sessions still varies by use case, the raw capacity gives it unmatched potential for users dealing with massive content projects.

2nd – Grok 4 demonstrates remarkable long-context performance through its 256k token window and strong real-world reasoning. It topped the ARC-AGI-2 benchmark, which means it can also sustain logic over extended steps. Combined with its agentic capabilities and native tool integrations, Grok is already production-ready for complex thinking at scale.

3rd – Claude Opus 4 supports 200k tokens and complements this with a hybrid reasoning mode that enables both fast, shallow responses and deep, structured thinking. Its stability is proven in a 7-hour refactor test, showing excellent consistency in long-form technical sessions. Claude remains a reliable partner for structured, memory-heavy tasks — though Grok edges it out in resourcefulness and problem-solving depth.

4th – GPT-4o carries a 128k token context limit inherited from GPT-4 Turbo. It performs well across most academic and business workflows but lacks the ultra-long memory and adaptive reasoning modes of its rivals. For casual use or structured queries, it’s more than sufficient, but for extreme document workloads, it might trail behind.

Multimodal Tasks (Text + Image / Audio / Video)

Multimodality is the next frontier in AI, combining different input types (like voice, images, or video) to make the model more useful and intuitive. This section looks at how well each model understands and integrates across modalities. True multimodal intelligence means fluid transitions between formats, like describing a photo with emotional nuance or responding to voice tone in conversation.

1st – Gemini 2.5 Pro takes the lead with its support for all four major input types: text, image, audio, and even video. This makes it the most versatile multimodal model currently available. It performs strongly in structured workflows like diagram analysis, form understanding, and video frame interpretation — especially in Google’s own internal demos. While its integration feels slightly more tool-assisted than GPT-4o, its sheer range of supported modalities earns it the top spot.

2nd – GPT-4o remains the most fluid and natural in multimodal interaction. It was trained end-to-end across text, vision, and audio, allowing it to handle tone, multiple speakers, and background noise with remarkable speed and precision. Its current support for voice and image inputs (even in the free ChatGPT app) is unmatched in terms of accessibility. While video input is on the roadmap, it’s not yet fully live, placing GPT-4o just behind Gemini in terms of input diversity.

3rd – Claude Opus 4 supports both image inputs and voice interaction, and it performs solidly in visual understanding — particularly in context-rich environments like charts, documents, and research papers. However, its multimodality still feels fragmented rather than fully unified, and it does not yet handle video inputs. These limitations place it behind the more seamless and integrated experiences offered by Gemini and GPT-4o.

4th – Grok 4 supports image and text inputs, and introduced a voice output feature called Eve. While it’s capable of interpreting photos and offering spoken responses, it still lacks full end-to-end multimodal training and does not support several inputs/outputs that its competitors do. Compared to more seamless systems like GPT-4o, Grok’s multimodal capabilities are more limited and remain primarily text-focused. For now, it lags behind in integrated media workflows.

Creative Writing & Tone

For many users, one of the most important aspects of an AI assistant is how well it writes. Whether it’s storytelling, brand copy, emotional tone, or nuanced humor, creativity is where language models become real companions. In this section, we’re evaluating the models based on their writing style, tone control, narrative flow, and ability to adapt to human-like expressions.

1st – Claude Opus 4 is the clear favorite for writing that feels “human.” It’s especially good at capturing tone, emotion, and voice — whether you need poetic language, witty responses, or deep, empathetic prose. Claude is often praised for generating text that is grammatically flawless and feels subtly “alive”. Writers and content creators consistently turn to Claude when they need help with creative endeavors.

2nd – Grok 4 delivers bold, sharp, and often witty writing that feels full of character. While it’s known for its humorous tone, it can also shift into professional and serious language when needed. Its concise, confident output is ideal for scripts, marketing lines, or opinionated summaries. Although it lacks the emotional softness of Claude, its stylistic personality and adaptive tone make it a strong contender for creative and persuasive writing.

3rd – GPT-4o offers strong control over tone, structure, and formatting. Its outputs are clean, logically coherent, and highly adaptable — great for essays, blog posts, or educational content. However, compared to Claude or Grok, its written tone can occasionally feel more neutral than expressive.

4th – Gemini 2.5 Pro is precise and polished but leans towards a more technical tone. While it performs well in structured writing like reports or technical descriptions, it tends to fall short in emotional nuance or artistic rhythm. For creative writers and marketers, this makes Gemini more of a productivity tool than a stylistic partner.

Agentic Behavior & Tool Use

Agentic behavior refers to an AI model’s ability to take action — like navigating tools, using external functions, or reasoning across steps to accomplish a task. This is critical for hands-on usage of research assistants, and coding agents. Here we are looking at models that act with intention.

1st – Grok 4 dominates this category. It’s specifically designed for working with tools, making decisions on the fly, and handling complex tasks that require reasoning rather than simple data recall. Its ability to break problems into steps, use external functions, and adapt its behavior based on live context makes it really feel like an “AI co-pilot”. In practice, it’s proven very powerful in active decision making and software workflows.

2nd – Claude Opus 4 is a strong contender thanks to its multi-mode architecture, which allows it to switch between quick chat and “slow thinking” chains for complex tool use. Claude can follow structured workflows, handle long-range plans, and is increasingly used in AI agents. Its reasoning is consistent and explainable, making it reliable even when things get complicated.

3rd – Gemini 2.5 Pro integrates well into the Google ecosystem, including Workspace and Android, and has shown strong early results in agentic coding demos. It handles tool use well when APIs and workflows are clearly defined, especially in enterprise environments. However, its autonomy and memory chaining aren’t yet as developed as Grok or Claude.

4th – GPT-4o lags slightly in this category. While it supports functions, tools, and memory in ChatGPT, its behavior remains largely prompt-driven. It does not yet show the same level of autonomous action-taking, and tool use often requires setup or pre-built agents. Its strength is in reliable execution, not adaptive strategy.

Up-To-Date Knowledge

In a world that changes by the hour, having up-to-date information is essential for tasks like news analysis, market updates, or fact-checking. This section evaluates how each model handles current events, live data, and real-time awareness.

1st – Grok 4 stands out with its real-time access to X (formerly Twitter), giving it a unique edge in tracking breaking news, trending topics, and cultural moments as they happen. Unlike most models that rely on static knowledge bases or occasional updates, Grok is built for real-time search and context. This makes it especially useful in journalism, finance, or social commentary.

2nd – Gemini 2.5 Pro has access to real-time Google Search, giving it strong capabilities in current event tracking, fact-checking, and answering up-to-date queries. It performs well across a range of recent topics and integrates tightly with Google Workspace and extensions like Gemini in Chrome. Its search responsiveness makes it highly effective in fast changing or research heavy environments.

3rd – Claude Opus 4 supports live web browsing, enabling it to retrieve real-time information, verify facts, and include source links in its responses. While its browsing feature is not yet as tightly integrated as Grok’s or Gemini’s, Claude combines this access with strong reasoning skills, making it a well-rounded assistant for research and current topics.

4th – GPT-4o provides basic real-time information through its browser tool in ChatGPT, but its performance can vary. While it can return fast answers and sources, users have occasionally reported hallucinated links or broken citations. This inconsistency places GPT-4o behind Claude and Gemini when it comes to reliable, up-to-date data access — despite its otherwise powerful capabilities.

Special mention – Perplexity AI deserves recognition for its laser focus on up-to-date information. While not part of the main four models in this comparison, it is built specifically for real-time knowledge retrieval. Whether you’re exploring breaking news or searching for the most relevant sources on a niche topic, Perplexity consistently delivers reliable, well-cited information, making it one of the top tools for anyone prioritizing truthful, source-backed insights.

Technical Benchmarks

While everyday users care about results, technical benchmarks remain a popular way to measure model performance across domains like math, logic, coding, and reasoning. Let’s look at how each model performs across industry-standard tests like MMLU (understanding and applying knowledge across a wide range of fields), GPQA (graduate-level answers in STEM subjects), SWE-Bench (practical coding tasks), and HLE (test of human-like thinking).

But there is a caveat: although benchmarks look fancy and may be useful for comparing technical performance, they don’t always reflect real-world experience. AI labs are increasingly optimizing models specifically to perform well on known benchmarks, which can sometimes lead to inflated scores without equivalent real-world gains. That’s why it’s important to evaluate each model not just by numbers, but also by how well it supports your use cases in daily life.

How to Choose the Right Model For You?

Choosing the best AI model depends on what you need. Each of these models brings something different to the table, and the right one will depend on whether you value reasoning, speed, creativity, cost, or cutting-edge features.

• Pick GPT-4o if you want the best all-around AI assistant for everyday tasks. It’s the top choice for general users who need help with writing, organizing, answering questions, or solving common problems, all in a fast, intuitive interface. With strong multimodal abilities (text, voice, image) and wide availability in the free ChatGPT app, GPT-4o remains the most accessible and user-friendly option.
• Pick Grok 4 if you want bold reasoning, real-time knowledge, and the closest thing to autonomous AI behavior available today. It’s ideal for researchers, technical users, and anyone who needs high performance logic combined with intentional tool use. While not a fully independent agent yet, Grok is clearly leading the way toward that future.
• Pick Claude Opus 4 if you care about writing, empathy, and human-like thoughtfulness. It’s the most balanced model for general use, and particularly valuable for professionals in law, marketing, writing, or education.
• Pick Gemini 2.5 Pro if you want reliable performance, seamless integration with Google tools, and strong multimodal capabilities. It’s especially useful for developers, data analysts, and professionals working inside the Google Workspace ecosystem, where its tight integration and stable outputs shine.

Each of these models is a dominant AI system. The choice you make should reflect your needs, not just the leaderboard scores.

Conclusion

The competition for the best AI assistant in 2025 is really about choosing the model that best aligns with your priorities. Grok 4 leads in raw reasoning, agentic behavior, and benchmark dominance, pushing the limits of what AI can do in technical, creative, and up-to-date research tasks. Claude Opus 4 brings unmatched clarity in communication, long session thinking, and emotionally intelligent writing, making it perfect for dialogue and thoughtful output.

Gemini 2.5 Pro shines in its tight integration with Google’s ecosystem and excels in multimodal tasks across voice, text, video, and image. GPT-4o, meanwhile, offers perhaps the most user-friendly experience — fast, intuitive, and versatile — especially for casual users exploring the full spectrum of AI capabilities.

The real question is which AI gets your job done faster, better, and with fewer limitations.