AI rereads everything before answering. Every time.
And the longer the chat runs, the more expensive and worse it gets.

ContextCoach is a Chrome extension that helps slash waste.

Add to Chrome — Free

Free · No API key · Works on 🟣 Claude.ai & 🟢 ChatGPT

The problem

Two things working against you —
and most users don't see either.

A person overwhelmed by a massive pile of AI context tokens
📄

Every query re-reads everything

Your conversation history, uploaded PDFs, project files: the AI processes almost all of it every turn. Even with some 'caching', these models read the bulk of your context each time. A single PDF can add 50,000 to 200,000 tokens before you type a word.

📉

Quality degrades as context grows

Accuracy drops 20–30% as context fills. Relevant information buried mid-conversation gets under-weighted. Responses get vaguer and less precise — which means more back-and-forth to fix them.

Source: "Lost in the Middle," Stanford / UW, 2023
🔁

Repair loops compound the cost

A degraded response means you re-explain, clarify, correct — adding more tokens to an already-bloated context. Each correction cycle burns processing and thus energy and water at data centers. A clean reset is almost always cheaper than five correction exchanges in a rotting context.

✓ Free ✓ No API key ✓ Nothing leaves your browser ✓ Open source (MIT)
How it works

A color-coded signal,
right at the top of your chat

No account. No API key. ContextCoach runs entirely in your browser and watches your context grow in real time.

●

Green — you're in good shape

Context is light. Keep going. The banner auto-collapses to a small pill so it stays out of your way.

●

Yellow — context is growing

It's worth thinking about a fresh start, especially if the topic has shifted. A Summarize Prompt button appears in the banner. Click it and ContextCoach injects a summary request into your chat. The AI writes a tight summary of everything important. Then a second button appears to open a new tab and load the summary. You're ready to go.

●

Red — reset now

Context is heavy. ContextCoach tells you exactly how much you'd save — e.g. "Starting fresh cuts cost and energy use by ~85%." The same two-click Summarize flow appears. A clean slate saves you money and energy.

Two clicks and you've mastered context.

Click Summarize Prompt → AI writes the summary → click Open in New Tab → done.

Add to Chrome — Free
What it looks like

ContextCoach in action on Claude.ai

ContextCoach green banner on Claude.ai

What appears on the top of your chat

Green · Yellow · Red — the three states

ContextCoach green, yellow, and red banners
What it tracks

Everything that drives your context load

Most tools only count message length. ContextCoach tracks the whole picture — including what other extensions miss.

💬

Conversation length

Every user message and AI response, accumulated across the session.

📎

Uploaded documents & PDFs

ContextCoach uses an estimate of 15 pages at 2,000 tokens per page for each PDF. When PDFs dominate, you get a special message in the pop-up: (click the extension icon)

🗂️

Project knowledge files

On Claude.ai, project files add tokens before the conversation starts. Other extensions don't count these.

🖼️

Uploaded images

Images you upload to the chat use tokens too. ContextCoach counts only your uploads — not the AI's icons or interface elements.

⚙️

Generated artifacts & code

Claude artifacts and ChatGPT canvas sessions add significant tokens that most counters miss.

🎯

Controllable vs. fixed costs

System overhead subtracted automatically — the color reflects only what starting fresh would actually save.

Free. No account. No backend.

ContextCoach runs entirely in your browser. Your conversations are never transmitted anywhere.

  • No API key required
  • No account or login
  • Nothing leaves your computer
  • Open source (MIT)
Add to Chrome — Free
About this site

masteringaifootprint.com

A home for tools and thinking around AI efficiency — what AI actually costs in compute, energy, and money, and how to get more value out of every query.

ContextCoach is the first tool. More coming.

Built by Andrew Winston, sustainability strategist and author. Follow along on Substack or LinkedIn.