Why do my ChatGPT custom instructions keep disappearing?

The most likely cause is a browser session issue. Try saving in a private window, clearing site data for ChatGPT's domain, or using a different browser. If the save appears to work but instructions are gone after a reload, a cached state is usually responsible.

Is there a character limit on ChatGPT custom instructions?

Yes. Each of the two fields has a character limit. If your text exceeds it, the save may fail silently or save only a truncated version. Check the current limit on OpenAI's help pages, as it has changed across updates.

Do custom instructions work inside ChatGPT Projects?

ChatGPT Projects have their own instructions that can override your global custom instructions. If you are working inside a Project and your global rules seem to have no effect, check whether the Project has its own instructions set.

Can I have more than one set of custom instructions?

ChatGPT's custom instructions are one global set. If you need different rules for different projects or tasks, you can switch the custom instructions manually, use a ChatGPT Project with its own instructions, or save named rule sets in a tool like fenbs and paste the relevant one at the start of each conversation.

My custom instructions saved but ChatGPT is still ignoring them. What should I check?

First confirm you are in a plain new conversation, not inside a GPT or a Project. Then check whether your instructions are long or dense — a clear, short rule at the top is followed more reliably than a buried instruction. The article on ChatGPT custom instructions not working covers the reliability side in more detail.

ChatGPT Custom Instructions Not Saving: What to Check

If your ChatGPT custom instructions are not saving or not sticking, there are a handful of specific causes. This guide walks through each one.

August 10, 2026Updated October 21, 20264 min read

If your ChatGPT custom instructions are not saving, the most common causes are account type restrictions, exceeding the character limit in one of the two fields, or a browser or session issue that is blocking the save request. Each has a specific fix.

Custom instructions are one of the most useful places to store reusable rules for how ChatGPT should respond. Tools like fenbs keep a similar record outside ChatGPT itself, so rules survive across apps and sessions even when custom instructions have limits.

Check your account type first

Custom instructions are available on certain ChatGPT plans and not others. If you do not see the option in Settings at all, your current account type may not include the feature. Check OpenAI's help pages (opens in a new tab) for the current list of plans that include custom instructions, since availability has changed across plan updates.

If you do see the fields but they will not save, you are past the account-type check and the problem is likely one of the issues below.

Check the character limit in each field

Custom instructions has two fields: one for background about yourself, and one for how you want ChatGPT to respond. Each field has a character limit. If you are near or over that limit, the save may silently fail or only save a truncated version.

Copy your text into a character-counting tool before pasting. Trim anything that is not essential. If your instructions are long, consider keeping a compressed version in custom instructions and saving the full version in a notes app or in fenbs where there is no character cap.

Try a browser fix

A stale session or cached state sometimes prevents the save from reaching OpenAI's servers. Try these steps before assuming the issue is permanent. In most cases, one of the first two steps resolves it without any further changes.

Open ChatGPT in a private or incognito window and try saving there. If it works, a cached session in your normal browser is the issue.
Clear the site data for chat.openai.com and chatgpt.com in your browser settings, then sign in again.
Try a different browser entirely to rule out a browser-specific conflict.
Disable browser extensions one at a time if you have many running. Some ad blockers or privacy tools block outgoing save requests.

Check whether a GPT or Project is overriding your instructions

Custom instructions apply to new conversations with the main ChatGPT assistant. They do not automatically apply inside a GPT you have opened, a ChatGPT Project, or a conversation where you have manually added a system message. If your instructions appear to save but then have no effect, the conversation may be running in one of these other contexts.

Check which context you are in before testing. Start a plain new conversation with no GPT selected, and no Project active, to confirm the instructions take effect. For more on the difference between these, the ChatGPT Projects vs custom GPTs article explains when each applies.

When saving works but instructions are not followed

A successful save does not guarantee the instructions will be followed in every response. Long or conflicting instructions can reduce reliability. A rule buried in the middle of a dense paragraph may carry less weight than one stated clearly at the top. Instructions that run to several hundred characters covering many different rules are more likely to be partially ignored than a short, focused set of two or three clear rules. For this problem, see the companion piece on ChatGPT custom instructions not working.

Keeping your instructions outside the character limit

The character limit in custom instructions is tight if you have built up a detailed style guide, a set of project rules, and background context over time. One approach is to keep the essential short rules in custom instructions and store the full text of each rule somewhere you can paste it into a conversation when needed. A compressed version of a rule often works just as well as the full version for everyday use, with the full version available for complex sessions where precision matters.

How fenbs helps

Keep reusable instructions where there is no character cap

fenbs Skills and prompts stores each of your reusable instructions as a named entry with no character limit. A connected AI app can read a skill by name at the start of a session, so you are not limited to what fits in custom instructions. When you update the instruction in fenbs, every future session gets the new version.

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How to do this with fenbs

Create a free account and open your board.
In Skills and prompts, add your finalized instructions as named skills, one rule or style guide per entry.
In Decisions and rules, record any standing rules that must never be ignored, such as "always cite sources" or "never suggest a price."
Connect your AI apps from Integrations. Ask each connected assistant to read your skills and rules at the start of a session.
When you update a rule, change it in fenbs once. The next session picks it up without any copy-pasting.

fenbs does not replace custom instructions if your only goal is to set a persistent style in ChatGPT. For that specific use case, fixing the save issue and keeping a short, focused instruction in ChatGPT's settings is the simpler path. fenbs helps most when the same rules need to travel across different AI apps.