OpenAI Publishes GPT-5.5 System Card Details

Per OpenAI's April 23, 2026 System Card, GPT-5.5 is a new model tuned for complex, real-world workflows such as code writing, web research, multi-step document and spreadsheet creation, and tool-enabled tasks. The System Card says OpenAI subjected the model to its full suite of predeployment safety evaluations and its Preparedness Framework, including targeted red-teaming for advanced cybersecurity and biological capabilities, and collected feedback from nearly 200 early-access partners before release. The System Card was updated on April 24, 2026 to add deployment safeguard details for the API. The card also documents a public jailbreak bounty program; Zvi quotes the card, "We have launched a public program that will allow selected (via invitation and application) researchers to submit universal jailbreaks." The System Card explains that GPT-5.5-Pro uses the same underlying model with larger allocations of parallel test-time compute and that, except where noted, results describe offline evaluations.

Zvi's blog post titled "GPT 5.5: The System Card" describes GPT-5.5 as a "solid improvement" and asserts that, for many purposes, GPT-5.5 is competitive with Anthropic's Claude Opus 4.7. Zvi frames GPT-5.5 as preferable for "just the facts" queries and well-specified tasks while suggesting Claude Opus 4.7 may be stronger on open-ended or interpretive prompts, and he recommends hybrid approaches for coding workflows. Zvi also notes the system card provides less detail than Anthropic's Mythos and Opus model cards and expresses reservations about the card's ability to surface new alignment problems.

Industry-pattern observations: model vendors increasingly publish system or model cards and run structured red-teaming and partner pilots before deployment. These disclosures vary in granularity; public comparisons such as those by Zvi reflect a common practitioner workflow of pairing vendor documentation with hands-on evaluations to assess strengths on narrow versus open-ended tasks. For practitioners, GPT-5.5's described emphasis on tool use and iterative task completion aligns with a broader shift toward models optimized for multi-step, tool-integrated workflows rather than purely conversational benchmarks.

Editorial analysis: observers will watch three indicators: the results of the public jailbreak program and any universal jailbreak disclosures; cross-lab benchmark comparisons if third parties or competing labs publish side-by-side evaluations; and usage signals from early-access partners about where GPT-5.5 or GPT-5.5-Pro materially changes productivity for code, research, or agentic tasks. Zvi's critique of limited transparency in the card highlights ongoing community demand for standardized, cross-lab test suites to enable robust comparisons.