DeepSeek V4.1 Flash vs Claude Opus and Haiku 5.5: A community room-building test
A Reddit creator gave DeepSeek V4.1 Flash 1017 and two Claude models the same JavaScript room-building task. Two comparison videos, followed by a separate harness test, raise a useful question: how much of a coding demo reflects the model, and how much reflects the tools around it?
By DeepSeek V4 Hub
Original tests and videos: u/Impressive-Chard-666 in r/DeepSeek
If a Reddit video does not play here, use the original-post link beneath it to watch on Reddit.
Reddit user u/Impressive-Chard-666 shared two comparisons of DeepSeek V4.1 Flash 1017: one against Claude Opus 5.5, and another against Claude Haiku 5.5. The creator describes giving each pair the same prompt to build a room in JavaScript.
The clips show the running scenes produced from code. They are examples of a visual coding task. Their appeal is immediate: readers can inspect the rooms themselves, rather than relying on a score.
Watch: DeepSeek V4.1 Flash vs Claude Opus 5.5
The Opus post introduces the room-building task. In the post, the creator says DeepSeek ran through its web interface. That detail matters when interpreting the result: matching the user prompt does not establish that both models had the same tools or opportunity to revise their code.
As you watch, separate the room's visual style from its behavior. Furniture placement and lighting are easy to notice; a broken interaction or an object passing through another may take longer to spot.
Watch: DeepSeek V4.1 Flash vs Claude Haiku 5.5
The second post pairs DeepSeek with Haiku 5.5 on the same kind of task. The creator's updated post also identifies the DeepSeek run as using the web interface and links to a later harness test.
The discussion includes both a preference for Claude's output and criticism of object overlap. Those are different judgments. A scene can look more polished while still containing layout problems, so visual appeal alone is an incomplete measure of the code.
What changed in the harness follow-up?
The creator published a separate Haiku comparison stating that DeepSeek now ran in a harness instead of the web interface. In a reply about reasoning settings, the creator specifies max for DeepSeek and xhigh for Claude.
A harness is the software around a coding model that manages its work and tool access. For a useful comparison, the record should explain whether each setup could run the code, inspect errors, and make further changes. Those opportunities can affect the finished scene.
This follow-up adds context to the first two videos. It does not, by itself, isolate the effect of the harness or establish a general ranking between the models.
Does the same prompt make this a controlled comparison?
The prompt is one part of the setup. To reproduce the comparison or judge efficiency, readers also need the execution conditions.
| Comparison | DeepSeek setup | Source detail |
|---|---|---|
| Against Opus 5.5 | Web interface | Creator identifies the interface in the post. |
| Against Haiku 5.5 | Web interface | Updated post points to the separate harness run. |
| Haiku follow-up | Harness; max effort | Creator reports xhigh effort for Claude in a reply. |
A repeatable test should keep a record of the exact prompt and model identifiers, tool permissions, attempts and edits, elapsed time, and token usage. The creator links a prompt document in the posts. This article does not report a measured cost or speed advantage.
What should developers take from the videos?
Use the clips to decide what you would test next. For a room-building task, check whether the output meets the requested layout, renders consistently, and remains usable when you interact with it. Then try a small change to see how well the code holds up.
These posts offer a concrete example of DeepSeek and Claude attempting the same visual coding task. A broader model choice needs more tasks and a documented budget. The linked follow-up is part of that story and belongs alongside the original comparisons.
This article summarizes the creator's posts and reported settings. DeepSeek V4 Hub has not independently reproduced the tests. Model names follow the original posts.
Sources
The tests and videos below were posted by u/Impressive-Chard-666 in r/DeepSeek. Article text and analysis are by DeepSeek V4 Hub.
- DeepSeek V4.1 Flash 1017 vs Claude Opus 5.5 Same Prompt Original Opus comparison, task description, and DeepSeek web-interface disclosure.
- DeepSeek V4.1 Flash 1017 vs Claude Haiku 5.5 Same Prompt Original Haiku comparison, updated setup disclosure, and discussion.
- DeepSeek V4.1 Flash 1017 vs Claude Haiku 5.5: harness follow-up Separate run and creator's reported reasoning settings.
- Creator-linked prompt document Shared by the creator in the original posts.