Model comparison · one run each
ChatGPT vs Claude vs Gemini on a 1-hour YouTube video
Claude Sonnet 5.5, GPT-6.1 Sol and Gemini 3.1 Pro got the same 1-hour MIT lecture, first as a YouTube link, then as its transcript. We scored every summary.
- Tested
- Updated
- Models
- 3
TL;DR
- Given only the link, Claude and GPT said they can’t open links and asked for the transcript, without guessing. Gemini watched the video through its API.
- Gemini answered all three questions right from the video, but its summary covered 3 of our 8 key points and said the lecture ends on advanced features. It ends with warnings.
- Given the transcript, Claude and GPT covered all 8 points and Gemini covered 7 (it left out MCP). All three got all three questions right, including a trap.
- The transcript was about 24,000 tokens; Gemini’s video input was 330,785, about 14 times more. Each transcript run cost $0.04 to $0.07.
Creatos asks GPT, Claude, Gemini and local models the same question about your own files, side by side. $69 once.
Download CreatosSetup
- App
- A short script calling each vendor’s API directly
- Machine
- Mac mini, Apple M4 (sends the requests; the models run in each vendor’s cloud)
- System prompt
- None
- Max output tokens
- 4,096
- Temperature
- Provider default
- Reasoning effort
- Provider default
- Web search and tools
- Off
- Gemini video resolution
- Default
- Runs
- One per round per model
Task
Prompt, identical for every model
Summarize this video in 8 bullet points. Then answer: 1. Which underlying language model does the lecturer say Claude Code is using in his demo? 2. What does the lecturer warn about at the end of the lecture? 3. What SWE-bench score does the lecturer quote for Claude Code?
Source: Lecture 7: Agentic Coding (Missing Semester, 1:00:34)
Each model got this prompt twice, as one user message. Round 1 put "Video: https://www.youtube.com/watch?v=sTdz6PZoAnw" above it; Gemini also got the link as a YouTube video part, which its API can watch. Round 2 put the lecture’s full English captions above it, inside <transcript> tags: 1,306 lines with timestamps, about 24,700 tokens. The trap: the lecture quotes no SWE-bench score.
The answers, side by side
Same source, same prompt, one run each
claude-sonnet-5-5
CloudAnthropic
- Total12 s
- Cost$0.06
Round 1: just the link
I can't open links or watch videos, and I don't know what's in this one from the URL alone. Any summary or answers I gave would be made up, including the model name, the closing warning, and the SWE-bench score, so I won't guess.
Here are some ways I can still help:
- Paste the transcript. On YouTube, click "...more" under the video, then "Show transcript," and copy the text here. I'll write the 8-bullet summary and answer your three questions from it.
- Share the key sections. If the transcript is too long, paste the parts about the demo, the closing remarks, and any benchmark discussion.
- Give me the title, lecturer, or course name. I can share general background on Claude Code, but I can't confirm what the lecturer said, so I wouldn't treat it as answers to your questions.
If you send the transcript, I'll also flag anything the lecturer leaves unclear. For example, if he doesn't name the model or gives no SWE-bench figure, I'll say so rather than fill in a guess.
Round 2: the transcript
Summary (8 bullet points)
- What coding agents are: A coding agent is a conversational AI model with access to tools (read/write files, run shell commands, search code) that lets it write and modify software on your machine. The lecture demos Claude Code turning a simple script into a proper CLI program with argparse and type annotations, checked with mypy.
- How they work under the hood: A language model is a conditional probability distribution over completion strings given prompt strings. Multi-turn chat is built by feeding the whole conversation history back in with turn markers. An agent harness wraps the model in a loop: it samples output, executes any tool calls, feeds the results back, and repeats until the model produces a final text reply.
- Safety and cost: The lecturer lets the agent edit files freely because he tracks everything in Git, but he approves shell commands individually. Costs depend on the model and usage (the demo cost about 19 cents). Hosted models send your data to the cloud, so privacy terms matter.
- Use cases: Implementing features, fixing bugs from failing tests (test-driven workflows), refactoring, code review, understanding unfamiliar codebases, acting as a natural-language shell, creative front-end work, and vibe coding.
- Workflow tips: Iterate over multiple turns, interrupt the agent when it goes off track, and give feedback loops such as tests, type checkers, and compilers. Prompt quality affects results, and complex features may warrant long prompts or a PRD.
- Parallelism and integrations: Run multiple agents at once, using git worktrees to give each an isolated copy of the repo. The Model Context Protocol (MCP) connects agents to external tools such as Notion.
- Context management: Models have limited context windows, so the lecture covers clearing context, rewinding the conversation, compaction (summarizing history), llms.txt (compact docs for LLMs), agents.md/claude.md (persistent project instructions), skills (on-demand instruction files), and sub-agents (isolating subtasks from the parent's context).
- Caveats: AI is not magic. Output can be subtly wrong, and verifying it can be harder than writing it yourself. Agents can go down rabbit holes, insist they're right, or spiral while debugging. Programming skills are still valuable, and students should follow their course's AI policies.
Answers
-
Underlying model: The lecturer says Claude Code is using Anthropic's Opus 4.5 model in the demo.
-
Closing warning: He warns that AI tools are powerful but make mistakes. Code can look reasonable yet be subtly wrong, and verifying it can take longer than writing it yourself. Agents can also go off the rails, gaslight you, or get stuck in debugging spirals that make the code worse. You should review output for correctness and security, and computer science skills remain valuable.
-
SWE-bench score: The lecturer never quotes a SWE-bench score for Claude Code, or mentions SWE-bench at all, so there is no figure to report.
Two requests, shown unedited. Round 1: 4.2 s, 135 input tokens, $0.0043. Round 2: 7.6 s, 24,805 input tokens, 1,008 output tokens, $0.0597. Every extra detail in round 2 is in the transcript, such as the demo costing about 19 cents [06:53].
gpt-6.1-sol
CloudOpenAI
- Total21 s
- Cost$0.04
Round 1: just the link
I can’t access or watch the YouTube video from its link in this chat. Please paste the video’s transcript (YouTube → Show transcript), and I’ll provide:
- A summary in 8 bullet points
- The underlying language model the lecturer says Claude Code uses in the demo
- The lecturer’s warning at the end
- The exact SWE-bench score quoted
I don’t want to guess at these video-specific details.
Round 2: the transcript
- Coding agents go beyond autocomplete: They combine a conversational language model with tools for reading and editing files, running shell commands, and completing development tasks end-to-end.
- The initial demo upgrades a Python script: Claude Code turns
dl.pyinto a command-line program usingargparse, adds type annotations, checks it withmypy, and runs it to verify its behavior. - An agent consists of a model and a harness: The model generates text or tool-call requests; the harness executes those requests and feeds results back into the model in a repeated loop.
- Effective workflows rely on iteration and feedback: Developers can refine instructions, interrupt misguided work, and use tests, compiler errors, or type-checker output to guide the agent toward a working solution.
- Agents support many development tasks: Examples include implementing features, fixing bugs, refactoring, reviewing code, explaining unfamiliar repositories, generating shell commands, and prototyping designs through “vibe coding.”
- Permissions, cost, and privacy matter: The lecturer recommends reviewing potentially dangerous tool calls, tracking changes in Git, monitoring usage, and understanding what data hosted providers receive and how they may use it.
- Advanced features improve productivity and context management: Reusable prompts, parallel agents with Git worktrees, MCP tool integrations, context clearing and compaction,
llms.txt, repository instructions, skills, and subagents help organize larger workflows. - Human judgment remains essential: Agents can produce subtly incorrect or insecure code, lose information during refactoring, and get stuck in unproductive debugging loops; programming skills and careful review remain valuable.
Answers
-
Underlying model: The lecturer says his demo uses Anthropic’s Opus 4.5 ([24:11–24:15]).
-
Warning at the end: AI is not magic and can make mistakes. He warns about plausible-looking but subtly wrong code, security bugs, rabbit holes, insistence on incorrect answers, and debugging spirals that worsen the code. He recommends reviewing outputs carefully and notes that critical tasks may be better done manually.
-
SWE-bench score: No SWE-bench score is quoted in the provided transcript.
Two requests, shown unedited. Round 1: 7.8 s, 86 input tokens, $0.0018. Round 2: 13.0 s, 19,203 input tokens, 456 output tokens, $0.0430. “Lose information during refactoring” refers to exercises that went missing when the course notes were refactored [36:03–36:15].
gemini-3.1-pro-preview
Cloud- Total90 s
- Cost$1.43
Round 1: just the link
Here is an 8-bullet point summary of the lecture on agentic coding:
- Introduction to Coding Agents: The lecture introduces coding agents as a more sophisticated evolution of AI-assisted coding, moving beyond simple autocomplete to conversational models equipped with tools to read/write files and execute shell commands.
- Practical Demonstration: A live demo showcases an agent (Claude Code) autonomously transforming a basic Python script into a fully functional command-line interface tool, complete with argument parsing, type annotations, and automated testing via
mypy. - Security and Autonomy: The lecturer emphasizes the security risks of allowing agents to run commands autonomously, strongly recommending a workflow where users must manually approve each tool call, especially shell executions.
- Cost and Model Selection: Using coding agents incurs costs based on token usage. Users can choose between powerful, expensive cloud-based models or cheaper, less capable local models depending on the complexity of the task.
- Underlying Architecture: The system is conceptually broken down into two main components: a core Large Language Model (LLM) and an "agent harness" (or scaffolding) that manages the interaction.
- LLM Fundamentals: LLMs are described as probabilistic models that generate text completions based on prompt strings. Crucially, they operate within the constraints of a limited "context window," meaning they can only "remember" a certain amount of text at a time.
- The Agent Harness Loop: The harness manages the agent by placing the LLM in a loop: it feeds the conversation history to the LLM, parses any requested tool calls, executes those tools on the user's machine, and feeds the results back into the LLM's context.
- Advanced Capabilities: The lecture concludes by exploring advanced agent features designed to handle complex workflows, including context compaction (summarizing old messages to save space), parallel agents, and spawning specialized "sub-agents" to handle discrete tasks.
Here are the answers to your questions:
- During the second demo, the lecturer states that the Claude Code agent is using Anthropic's Opus 4.5 under the hood (this is also visible on his terminal screen).
- At the end of the lecture, he warns that AI is not magic and will make mistakes. He notes that agents can introduce subtle bugs, confidently give incorrect answers ("gaslight" you), or get stuck in debugging loops. Therefore, he cautions that strong computer science and programming skills are still essential so that developers can accurately review, verify, and correct the AI's output.
- The lecturer does not quote a SWE-bench score for Claude Code, nor does he mention SWE-bench at any point in the video.
Round 2: the transcript
Here is a summary of the video in 8 bullet points:
- Introduction to Coding Agents: The lecture introduces agentic coding, defining coding agents as conversational AI models (like ChatGPT) that are equipped with tools to autonomously read and write files, as well as execute shell commands.
- Live Demonstration: The instructor demonstrates a command-line agent (Claude Code) completing an end-to-end task. The agent reads a Python script, writes code to add argument parsing, runs a type checker (
mypy), and fixes issues—all while asking the user to approve commands that change the system state. - Underlying LLM Mechanics: At their core, Large Language Models (LLMs) function by modeling a probability distribution over output strings based on input prompts. For multi-turn chats, the entire conversation history, separated by turn markers, is continuously fed back into the model's limited context window.
- The Agent Harness/Scaffolding: The LLM is wrapped in an "agent harness." This harness runs a loop where it interprets the LLM's requests to use tools (like reading a file or running bash), executes those actions on the computer, and feeds the resulting text output back into the LLM as a new input prompt.
- Practical Use Cases: Beyond writing new features, coding agents are highly effective for test-driven bug fixing, codebase refactoring, code review, explaining unfamiliar codebases, acting as a natural language terminal shell, and "vibe coding" (creative front-end development).
- Advanced Workflows: The lecture highlights using multiple agents in parallel on the same codebase to save time. This pairs exceptionally well with tools like
git worktree, which allow users to spin up isolated branches so agents don't conflict with one another. - Context Management Strategies: Because LLMs have limited context windows and degrade when overloaded, agent harnesses use tools like context compaction (summarizing past messages), history rewinding, sub-agents, and standardized text files (
llms.txt,agents.md) to keep the model focused and efficient. - Limitations and Human Oversight: The lecture concludes by stressing that AI is not magic. AI tools can generate code that looks correct but harbors subtle logic or security bugs, get stuck in endless debugging loops, or hallucinate/gaslight the user. Human programming skills and careful code review remain strictly necessary.
Answers to your questions:
1. Which underlying language model does the lecturer say Claude Code is using in his demo?
The lecturer explicitly states that it is using Anthropic's Opus 4.5 large language model (mentioned at [24:09]).
2. What does the lecturer warn about at the end of the lecture? He warns that AI is not magic and can make mistakes. Specifically, he cautions that AI will often generate code that looks reasonable at first glance but is subtly wrong or contains security flaws. He also warns that agents can go off the rails, go down rabbit holes, stubbornly try to gaslight the user, or get stuck in "debugging spirals" where they continuously fail to fix a test. Because of this, human programming skills and careful review are still essential.
3. What SWE-bench score does the lecturer quote for Claude Code? The lecturer does not mention a SWE-bench score at any point in this transcript.
Two requests, shown unedited. Round 1 got the link as a YouTube video part: 70.2 s, 330,785 input tokens, 2,070 output tokens including thinking, $1.3604 at list price, though Google lists YouTube input as free while in preview. Round 2: 19.5 s, 23,740 input tokens, 2,166 output tokens including thinking, $0.0735. In round 1 the last bullet is wrong: the lecture ends with warnings, not advanced features [58:42–60:15]. In round 2, mypy found no issues to fix [25:59], and the Opus 4.5 line is at [24:11].
Measurements
Summary: which of our 8 key points each one covered
| Key point | Where in the lecture | Gemini, link (video) | Claude, transcript | GPT, transcript | Gemini, transcript |
|---|---|---|---|---|---|
| K1. A coding agent is a model plus a harness that runs its tool calls in a loop | [12:36–12:45], [20:05–20:32] | Yes | Yes | Yes | Yes |
| K2. File edits allowed without asking (tracked in Git); shell commands approved one by one | [04:42–05:36] | Partly | Yes | Yes | Yes |
| K3. Fix bugs by writing a failing test first; agents work well with feedback loops | [11:01–11:31], [28:42–29:04] | No | Yes | Yes | Yes |
| K4. Use cases: refactoring, code review, codebase understanding, agent as a shell, vibe coding | [35:43–41:37] | No | Yes | Yes | Yes |
| K5. Parallel agents, each in its own git worktree | [43:26–45:18] | Parallel agents only | Yes | Yes | Yes |
| K6. Model Context Protocol (MCP) connects agents to other tools, e.g. Notion | [45:27–46:08] | No | Yes | Yes | No |
| K7. Context management: clear, rewind, compaction, llms.txt, AGENTS.md, skills, sub-agents | [46:15–57:22] | Yes | Yes | Yes | Yes |
| K8. Closing warning: not magic, review output, subtly wrong code, debugging spirals, skills still matter | [58:42–60:15] | No (says it ends on advanced features) | Yes | Yes | Yes |
| Points covered | 3 of 8 | 8 of 8 | 8 of 8 | 7 of 8 |
The three questions
| Question | Right answer | Claude, link | GPT, link | Gemini, link (video) | Claude, transcript | GPT, transcript | Gemini, transcript |
|---|---|---|---|---|---|---|---|
| Q1. Model in the demo | Opus 4.5 [24:11] | Declined | Declined | Right | Right | Right | Right |
| Q2. Closing warning | Not magic; review the output; subtly wrong code; gaslighting and debugging spirals; skills still matter [58:42–60:15] | Declined | Declined | Right | Right | Right | Right |
| Q3. SWE-bench score (trap) | None is given | Declined | Declined | Right: none | Right: none | Right: none | Right: none |
Time, tokens and cost per request
| Model | Round | Seconds | Input tokens | Output tokens | Cost (USD, list price) |
|---|---|---|---|---|---|
| claude-sonnet-5-5 | Round 1: link | 4.2 | 135 | 403 | 0.0043 |
| gpt-6.1-sol | Round 1: link | 7.8 | 86 | 163 | 0.0018 |
| gemini-3.1-pro-preview | Round 1: link (video) | 70.2 | 330,785 | 2,070 | 1.3604 |
| claude-sonnet-5-5 | Round 2: transcript | 7.6 | 24,805 | 1,008 | 0.0597 |
| gpt-6.1-sol | Round 2: transcript | 13.0 | 19,203 | 456 | 0.0430 |
| gemini-3.1-pro-preview | Round 2: transcript | 19.5 | 23,740 | 2,166 | 0.0735 |
How we tested
- Before running anything, we read the whole transcript and wrote an answer key: 8 points a good summary of this lecture has to include, each with its timestamps, and the answers to the three questions. No model saw the key.
- Each model got one request per round: the prompt above, after either the link (round 1) or the full transcript (round 2). No system prompt, up to 4,096 output tokens, temperature and reasoning left at each provider’s default, no web search or tools.
- One run per round per model on 9 October 2026, with no retries. Seconds are wall-clock time per request as measured by our script. Token counts are the ones each API reported; Gemini’s output counts include its thinking tokens.
- Cost is those token counts times each vendor’s list price on the day. Gemini’s round 1 prompt was over 200,000 tokens, so it is priced at Gemini 3.1 Pro’s higher rate. Google’s docs list YouTube video input as “in preview and is available at no charge”, so the real bill for that request may be lower.
- We checked every bullet and answer against the transcript. A point counts as covered when a bullet states it, in any words. A line counts as wrong when the transcript says otherwise.
The transcript is the video’s human-made English captions, downloaded without the video. This is one lecture and one run per model, so read it as a spot check, not a ranking.
Source
Lecture 7: Agentic Coding (Missing Semester, 1:00:34)
- Credit:
- Missing Semester, MIT
- License:
- Creative Commons Attribution (CC BY)
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FAQ
Can ChatGPT or Claude summarize a YouTube video from its link?
Not through their APIs in this test: with web tools off, both said they can’t open links and asked for the transcript, and neither made anything up. Paste the transcript instead; with it, both covered all 8 of our key points.
Can Gemini watch a YouTube video?
Yes. Gemini’s API accepts a public YouTube link as video input, and here it answered all three questions right from the video. Its summary was weaker than its answers: it covered 3 of our 8 points and got the ending wrong, so check a video summary against the video.
What is the most reliable way to summarize a YouTube video with AI?
Start from the transcript. On YouTube, open it from the video’s description, copy it, and paste it into the assistant. Ask for timestamps so you can check each point, and add one question you already know the answer to.
Related tests
All model testsModel names are used for identification only. Creatos is not affiliated with OpenAI, Anthropic, Google, Meta, Alibaba or Ollama.