The free tier exists for you to test. Not to scale on it.
But before paying anything, you need to know what each free layer really includes, when it hits the limit with normal operations, and in which cases the tool isn’t the right answer even if it’s free. This guide organizes 12 tools by category with a mid-market ES criteria: company with 50 to 500 people, 5-50M EUR, without a dedicated technical team for AI.
Why This Matters
Most “free AI tools” guides mix Notion AI with LangChain as if they were equivalent. They’re not. For a mid-sized Spanish company, the criteria isn’t the price: it’s whether the tool fits without creating integration debt, without requiring an ML engineer to maintain it, and without generating tool sprawl that nobody governs.
Two years before buying an enterprise license, the mid-sized company should have validated a concrete use case with the free tier and measured real impact. This table accelerates that process.
The 12 Tools: Decision Table
LLM Chat (3)
| Tool | Real Free Tier | Operational Limit | Upgrade Trigger | Best Use Case | When NOT |
|---|---|---|---|---|---|
| Claude claude-sonnet-4-5 (web) | Daily usage with message cap | ~20-30 msgs/day in intense use | Team >3 people using daily | Complex writing, document analysis, strategic briefings | If you need API integration from day 1 |
| ChatGPT (GPT-4o free) | Message limit every few hours | Saturation in intense use >5 people | Need GPT-4 without throttling or plugins | Idea generation, first draft, quick response | If your case is structured data analysis — use something with native integration |
| Gemini (Google Workspace) | Free with personal Google account; in Workspace depends on plan | Limited Workspace integration in free | If your company is already on Google Workspace and wants native access in Docs/Gmail | Email summary, first draft in Docs, web context search | If you need output consistency — Google models have more voice variability |
Automation (2)
| Tool | Real Free Tier | Operational Limit | Upgrade Trigger | Best Use Case | When NOT |
|---|---|---|---|---|---|
| n8n (self-hosted) | Unlimited free in self-hosted | Requires own server (Hetzner €5/month) | When server maintenance cost is higher than cloud license | Automations between internal apps, CRM-ERP sync, operational alerts | If you don’t have someone to maintain a server. n8n’s free cloud tier has hard caps |
| Make (ex Integromat) | 1,000 operations/month free | Achievable with a single daily active flow | Any flow processing more than 30 records/day regularly | Quick no-code integrations, simple linear workflows | If your flow has complex logic with branches and errors — Make becomes expensive quickly |
Analytics (2)
| Tool | Real Free Tier | Operational Limit | Upgrade Trigger | Best Use Case | When NOT |
|---|---|---|---|---|---|
| Metabase (self-hosted) | Unlimited free in self-hosted | Requires own infrastructure | When you need SSO, automatic alerts, or embedding in external apps | Internal dashboards on your own database, without depending on analysts | If you don’t have your own database — Metabase isn’t your entry point |
| Umami (self-hosted) | Free, privacy by default | Requires own PostgreSQL | Only if maintenance exceeds SaaS cost (€9/month cloud) | Alternative to GA4 without cookies, GDPR-native, for your own websites | If you need paid campaign attribution — Umami doesn’t have that module |
CRM (1)
| Tool | Real Free Tier | Operational Limit | Upgrade Trigger | Best Use Case | When NOT |
|---|---|---|---|---|---|
| HubSpot Free | Basic CRM free forever | No automatic sequences, no native AI in free | 2 active salespeople or need for email sequences | Basic sales pipeline, contacts, manual follow-up | If you sell B2B with long cycle and need automation — in free it’s pure manual |
Email (1)
| Tool | Real Free Tier | Operational Limit | Upgrade Trigger | Best Use Case | When NOT |
|---|---|---|---|---|---|
| Resend | 3,000 emails/month, 100/day free | Daily cap is the real operational limit | Any automatic send >100 emails/day | Transactional emails from your own apps, confirmations, alerts | If you need marketing newsletter — Resend is technical infrastructure, not campaign platform |
Docs / Knowledge (1)
| Tool | Real Free Tier | Operational Limit | Upgrade Trigger | Best Use Case | When NOT |
|---|---|---|---|---|---|
| Notion (free) | Unlimited pages; AI is paid (~€10/user/month) | No AI, no advanced version history in free | When team exceeds 10 people or needs native AI in docs | Internal wiki, knowledge base, simple project management | If you already have Confluence or SharePoint — adding Notion creates context duplication |
Search / RAG (1)
| Tool | Real Free Tier | Operational Limit | Upgrade Trigger | Best Use Case | When NOT |
|---|---|---|---|---|---|
| Perplexity (free) | Web searches with AI, cap in Pro mode | Standard mode without own documents in free | Need to upload own documents or connect internal sources | Market research, quick competitive benchmarking, public documentation summary | If you need RAG on internal documents — Perplexity free isn’t for that |
Monitoring (1)
| Tool | Real Free Tier | Operational Limit | Upgrade Trigger | Best Use Case | When NOT |
|---|---|---|---|---|---|
| Sentry (free) | 5,000 events/month in free | A single error in loop can consume quota in hours | When event volume exceeds free tier or need retention >30 days | Error monitoring in your own apps, alerts when something breaks | If you don’t have your own app — without your own code, Sentry doesn’t apply |
Cross-Pattern: Free Tier is for Validation, Not Operation
The most common mistake in mid-sized companies: deploying a free tier in production and forgetting it. It works until it doesn’t — and the cost of forced migration under pressure is always higher than paying from the start.
Operational rule: free tier maximum 90 days per use case. If in 90 days you can’t measure concrete impact (hours saved, errors reduced, sales cycles shortened), turn off the tool. If you can measure it, you already have budget justification.
Recommended Minimum Stack for Mid-Market ES
Four tools that cover 80% of cases without integration overhead:
| Layer | Tool | Real Minimum Cost | What it Resolves |
|---|---|---|---|
| Work LLM | Claude Pro or ChatGPT Plus | €20-25/user/month | Writing, analysis, internal synthesis |
| Automation | n8n self-hosted | €5-10/month infra | Flows between apps, data sync, alerts |
| Web Analytics | Umami self-hosted | €5-10/month infra | GDPR-native web metrics without Google dependency |
| Monitoring | Sentry free→growth | €0-26/month | Visibility on what breaks |
Total: €30-70/month for a basic governed operation. Less than most SaaS subscriptions that mid-sized companies have dormant.
What this stack doesn’t cover: RAG on internal documents, advanced sales automation, BI on ERP. For those layers, you need budget and decision criteria before tooling.
Global Anti-Pattern
Buying enterprise licenses for tools you haven’t even used in free tier. If the free tier didn’t generate a clear use case, enterprise won’t either — it will just cost more.
Related
- AI Tool Sprawl: when having too many tools destroys decision
- AI Stack for Mid-Market: ERP, CRM, BI and automation without noise
- AI Portfolio Hygiene: fewer use cases, better
Translated from the Spanish original with AI assistance and reviewed for accuracy. Read the original in Spanish.