TL;DR: GPT-6.1 Sol and Claude Opus 5.5 shared the top result of the Sep 30, 2026 test. Both saved every answer and both photos from a phone form, and both put the follow-up change live. GPT-6.1 Sol did it three times out of three, with one teacher page that misread its saved answers. Claude Opus 5.5 did it once, opened in the look the brief asked for, and turned away an oversized photo before the upload. Try the same kind of request in Taskade Genesis.
What TSK-1 Found
Both models received the same request, word for word, on Sep 30, 2026. It came from a real customer: a family intake form that parents fill in on a phone, with two to four photos, and a teacher page that lists every family. After the first build we asked for one more question on the form. We opened every app, submitted the form with real photos, read the saved entry back, checked the teacher page, and checked that the change went live.
| Model | Builds | What the app did | Result |
|---|---|---|---|
| GPT-6.1 Sol | 3 | All three saved every answer and both photos, and every follow-up change landed. One teacher page misread its saved answers. | Works |
| Claude Opus 5.5 | 1 | Saved every answer and both photos, turned away an oversized photo, and opened in the cream look the request asked for. The follow-up change landed. | Works |
See the full evidence at /tsk/gpt, /tsk/claude, and the TSK-1 hub.
Test setup: These builds come from Taskade's TSK-1 benchmark tests. GPT-6.1 Sol is in the Taskade model picker on every paid plan. Claude Opus 5.5 is not. In your own workspace, Claude runs on your own Anthropic key, in automations and in custom agents on Enterprise.
GPT-6.1 Sol: The Same Result, Three Times
The strongest thing about GPT-6.1 Sol in this test is repetition. We ran the request three times. All three forms saved every answer and both photos. In all three, parents could fill in the form without an account, as the request asked. All three added the new teacher question, saved it with each submission, and put the change live.
The teacher page is where one build slipped. In two of the three builds, the teacher page listed every family with their photos. In the third, the page read the saved answers wrong and showed "No photos saved" for an entry that was complete. The photos were there. The page did not read them back. That is the kind of miss you only catch by opening the app, which is why every TSK-1 result starts there.
GPT-6.1 Sol was also plain about what it had not done. Every closing summary said what it had not tested, and pointed out that the teacher page was open to anyone with the link. For a form that holds children's photos and parent contacts, that note is the first thing an owner needs to read.
Claude Opus 5.5: The Brief, Down to the Look
The strongest thing about Claude Opus 5.5 in this test is finish. Its form saved every answer and both photos. It checked photo size before the upload started and turned away a 12 MB photo, so a parent learned about the limit before waiting on a slow upload. It was the only build of the test that opened in the light cream look the request asked for. The follow-up teacher question landed and went live.
Its class assistant answered questions about the class, but it could not count the families, so it could not say how many had signed up.
Claude Opus 5.5 also took an earlier test, on Sep 22, 2026: a match tracker for one player. Before it built, it asked where the weekly recap should go and who would use the tracker. Then it built three pages and a coaching automation that wrote a note into a logged match, at a far higher cost than the economical models in that test. GPT-6.1 Sol did not take that test, so it is Claude-only evidence, not a head-to-head.
Choose GPT-6.1 Sol If…
- You want a result that held up across repeat builds. Three builds of the same request, and all three saved every answer and both photos and landed the follow-up change.
- You want the model to tell you what it did not check. Every GPT-6.1 Sol closing named what it had not tested and flagged the public teacher page.
- You want it without a key of your own. GPT-6.1 Sol is in the Taskade model picker on every paid plan, with no separate API account to connect.
Choose Claude Opus 5.5 If…
- The look of the app has to match the brief. It was the only build of the test that opened in the cream look the request asked for.
- Parents will upload photos from a phone. It turned away an oversized photo before the upload started, instead of after.
- You want questions before the build. On the Sep 22, 2026 match tracker it asked where the recap should go and who would use the app before it wrote anything.
- You already have an Anthropic account. Claude runs in Taskade on your own Anthropic key, in automations and in custom agents on Enterprise.
The Taskade Angle: Route, Don't Standardize
Taskade routes across frontier models from top AI labs inside one workspace, and you set the model per agent or per automation step. A first build on GPT-6.1 Sol and, on Enterprise, a Claude Opus 5.5 agent on your own Claude API key can share one app, one set of projects, and one memory. Leave a step on TSK-1 Auto and Taskade picks the model for you.
Final Word: Repeat Builds vs First-Try Finish
GPT-6.1 Sol and Claude Opus 5.5 shared the top result of the same test. GPT-6.1 Sol's case rests on three builds that each saved everything, with one teacher page that needed a fix. Claude Opus 5.5's case rests on one build that matched the brief down to its colors and checked photo size up front. That is one test and four builds between them, so treat it as a direction. We will add builds as new tests run.
▲ Memory feeds Intelligence. ■ Intelligence triggers Execution. ● Execution creates Memory. Two frontier models. One workspace.
Build your own intake form in Taskade Genesis →
Related reading
- GPT vs Claude - The two families across every test.
- Opus vs Sonnet - Which Claude tier fits which task.
- TSK-1 hub - The complete model test dataset.
