ChatGPT Token Limit Reached: How to Handle It in 2026

Quick Answer

When ChatGPT hits its token limit, responses truncate or error with "Message too long" or "Please shorten your message". Fix it by splitting content into chunks, summarizing earlier messages, or switching to a model with longer context.

• GPT-4o: 128K tokens context, 16K output max
• Split large docs into sections of ~50K tokens
• Start fresh chats for new topics to free context

Why This Happens

Every model has a maximum context window (input + output combined). GPT-4o handles 128K tokens (~96,000 words), o1 handles 200K. When you exceed this, the model silently drops the oldest messages or refuses the request. Long conversations, pasted documents, and large code files eat context fast.

Step-by-Step Fixes

Step 1: Check token usage

Rough estimate: 1 token = ~4 characters = ~0.75 words. 1000 words ≈ 1300 tokens. Use platform.openai.com/tokenizer for exact counts.

Step 2: Start a new chat for new topics

Each new conversation resets the context. Don't dump unrelated topics into one chat.

Step 3: Summarize earlier context

At message 20+, type: "Summarize our conversation so far in 300 words. I'll use the summary to start fresh." Copy summary → new chat.

Step 4: Split large documents

For a 300K-token document, split into 3 parts. Process each separately, then combine summaries.

Step 5: Remove noise from pasted content

Before pasting: delete HTML tags, repeated headers/footers, boilerplate disclaimers. Saves 20–40% tokens.

Step 6: Use code interpreter for large files

Upload files via the paperclip icon instead of pasting. ChatGPT reads chunks as needed, saving context.

Step 7: Switch to a longer-context model

• o1: 200K tokens
• Claude Sonnet 4.5: 200K tokens (1M beta)
• Gemini 2.5 Pro: 2M tokens

Step 8: Use "Custom Instructions" to save repeat context

Settings → Personalization → Custom Instructions. Put your role, preferences, and constants here instead of repeating each chat.

Step 9: For API users — use message truncation

Implement sliding window: keep system + last N messages, summarize older ones.

Step 10: Chunk and chain

For data analysis on a huge CSV: chunk the file, process each, then ask the model to aggregate.

When to Contact Support

• You paid for Plus but still hit aggressive limits
• Error message says "context exceeded" at under 50K tokens (likely bug)
• Upload fails silently on files under 512MB

Support: help.openai.com

Prevention Tips

• Structure long research across multiple threads by topic
• Use Projects (Plus feature) to organize conversations
• Keep system prompts concise — every token counts
• Pre-clean pasted content (remove tables you don't need)

FAQs

How many tokens is GPT-4o's limit? 128K context, 16K output.

What happens when I exceed it? Oldest messages drop silently, or you get "message too long" error.

Does ChatGPT summarize old messages automatically? No — it drops them. You must summarize manually.

Why does Plus hit limits faster? Memory, custom GPTs, and image inputs all add to token count.

Can I see my token usage? Not in ChatGPT UI; use the API dashboard or tokenizer tool.

What's the longest-context AI? Gemini 2.5 Pro at 2M tokens.

Does voice mode count tokens? Yes — transcribed audio is tokenized like text.

Conclusion

Token limits force discipline in prompt design. For seamless multi-model routing that handles context automatically, try Assisters AI.

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