Free competitive intelligence tools exist, and a developer can wire up a decent set in an afternoon: Google Alerts for news, changedetection.io on your own server for page diffs, and Google Trends for demand. Before you commit to the self-hosted route, try AyeWatch's Free Preview, which needs no card and does the reading for you; when you outgrow the preview, its paid plans start at $9 a month.
What free really costs
Free tools move the cost from your card to your calendar. You pay in setup time, in a server to keep running, and in noise: a keyword alert fires on every passing mention, and a raw page diff fires when a cookie banner changes. The question is not whether a tool is free but how many minutes a week its output takes to read. That is why the list opens with a tool that has a paid tier: its trial shows what low-noise output looks like.
1. AyeWatch Free Preview: try the low-noise version first
AyeWatch is an AI monitor for web pages, topics and public social accounts. Instead of a CSS selector or a keyword list, you write the condition in plain English, for example "alert me when the API pricing or rate limits on this page change", and it reads the page for meaning. Each update starts with a summary and the sources behind it.
The Free Preview is a trial rather than a plan you keep. Paid plans begin at $9 a month as of November 2026 and add email, Slack, Discord, webhooks and a REST API that lets you create and update monitors from code, plus an MCP server for AI agents.
2. Google Alerts: news by email
Google Alerts emails you when new results for a search show up in Google. You can set how often, which types of sites, the language and the region. It costs nothing and works well for a rare company or product name. Because it runs a search query, a common brand name can bring in plenty of unrelated results.
3. changedetection.io: open source, self-hosted
changedetection.io is on GitHub under the Apache-2.0 license, and you can run it yourself for free. You get page change detection and alerts to many notification services; you also get the job of keeping it updated. Its makers also sell a hosted plan for $8.99 a month, and their site says you can bring your own LLM key, from Anthropic, OpenAI, Ollama and others, for AI change summaries.
4. Visualping free plan: a few pages, with an API
Visualping's free plan covers five pages and includes AI change summaries and an important-or-not flag. Its pricing page says the REST API and MCP server come with every plan, the free one included, which makes it easy to script against.
5. Google Trends: is anyone searching for it?
Google Trends shows relative search interest from 0 to 100 over time and by region. It will not tell you what a rival shipped, but it shows whether the problem they solve is drawing more searches.
The free stack at a glance
| Tool | Free part | What you trade |
|---|---|---|
| AyeWatch | Free Preview, no card | A trial; paid plans from $9 a month |
| Google Alerts | Everything | Keyword matching, email only |
| changedetection.io | Self-hosted, Apache-2.0 | Your server and upkeep |
| Visualping | Five pages, API and MCP | Page diffs only |
| Google Trends | Everything | Relative numbers, no competitor detail |
A zero-budget setup that still works
Put your top rival's name in Google Alerts. Self-host changedetection.io for its changelog and docs. Check Trends monthly for your category term. Run AyeWatch's preview against the rival's pricing page, and compare how much reading each tool asks of you. If the AI summaries save more time than the self-hosted diffs, that is your answer on whether the paid plan is worth it.