GPT-4.1 API: Issues with HTML Formatting and Ignoring Prompt Instructions

API
1

Subject: GPT-4.1 API: Issues with HTML Formatting and Ignoring Prompt Instructions

Hi everyone,

I’m reaching out to share some challenges I’ve been facing with the GPT-4.1 API, hoping to find insights or solutions from the community.

HTML Formatting Issues:

I’ve noticed that GPT-4.1 often returns HTML content with improperly formatted tags. For instance:

Tags like

  • are returned as <li>, which causes rendering issues.

    Closing tags sometimes appear with irregular spacing, such as </ li >, leading to invalid HTML.

    These formatting inconsistencies are problematic, especially when integrating the output into web applications or content management systems.

    Ignoring Prompt Instructions:

    Despite providing clear and specific prompts, GPT-4.1 occasionally disregards the instructions. Examples include:

    Failing to adhere to specified output formats.

    Overlooking explicit directives, such as “Do not include markdown formatting.”

    This behavior is unexpected, especially considering GPT-4.1’s touted improvements in instruction adherence.

    Steps Taken:

    I’ve experimented with adjusting the temperature, frequency_penalty, and presence_penalty parameters, but these changes haven’t resolved the issues.

    Implemented post-processing scripts to correct HTML formatting, but this feels like a workaround rather than a solution.

    Until yesterday, everything was functioning normally. However, today I’ve been experiencing continuous issues with the ChatGPT API.

    Here’s an example of the HTML output I’m receiving:

    <li>They ignore the quality and structure of the soil: overly loose or clumpy areas will never yield upright flower stalks;&lt;/ li &gt;</li>
<li>They plant too shallowly or scatter bulbs on the surface—resulting in widespread drooping by late June;&lt;/ li &gt;</li>
<li>They apply too much fresh manure or nitrogen—leading to lush foliage and weak, “watery” stems;&lt;/ li &gt;</li>
<li>They don't mulch the planting after the first sprouts—the soil dries out and compacts at the base;&lt;/ li &gt;</li>
<li>They forget to regularly loosen the rows during summer—oxygen is lacking for the development of a strong root system;&lt;/ li &gt;</li>
<li>They support individual specimens with sharp stakes or wire directly at the base—bulbs get injured, leading to fungal infections;&lt;/ li &gt;</li>
<li>They massively cut the leaves long before flowering ends—the plant weakens physically!&lt;/ li &gt;</li>

    It also sometimes writes articles in multiple languages, even when only one language is specified!

    The image shows bilingual gardening instructions in Ukrainian and English, providing tips for planting bulbs, including selection, preparation, and timing for optimal growth. (Captioned by AI)
    The image shows bilingual gardening instructions in Ukrainian and English, providing tips for planting bulbs, including selection, preparation, and timing for optimal growth. (Captioned by AI)788×732 73.6 KB

    Has anyone else encountered similar issues with GPT-4.1?