Quick answer: AInvasion offers five free, no-sign-up tools for the practical questions around AI spending: a monthly cost calculator, a 10-model comparison matrix, a prompt token estimator, a 3-question decision quiz, and a 70+ term glossary. If you only have a minute, use the Token Estimator on one real prompt, then the Cost Calculator on your real traffic. Those two answer “What will this cost me?” better than any ranked list.
Why a calculator beats another “best AI tools” list
A ranked list answers a question nobody has: which tool is best in general? The questions people actually have are narrower:
- What will this cost at my volume?
- Which model fits my budget and context needs?
- What will this prompt cost before I send it?
Those questions have numerical answers, and a listicle can’t give you one. A tool can, because it takes your inputs and returns your result.
Insight: the wrong unit. Most pricing coverage compares dollars per million tokens. That unit hides what matters. Your bill depends on four things: your input/output mix, your cache hit rate, whether the work can run in batch, and how often a request has to be retried. The cheapest model per token is not always the cheapest model per finished task. The five tools below are built around these variables rather than around headline rates.
The five tools at a glance
| # | Tool | Type | Answers |
|---|---|---|---|
| 1 | AI Cost Calculator | Calculator | “What will my monthly bill be?” |
| 2 | AI Model Matrix | Sortable table | “Which models fit my price, context, and modality limits?” |
| 3 | Prompt Token Estimator | Calculator | “What will this exact prompt cost?” |
| 4 | Decision Quiz | Rule-based quiz | “Where do I even start?” |
| 5 | AI Glossary | Reference | “What does this term mean?” |
Privacy: According to AInvasion, the calculators and the matrix run entirely in your browser, so what you type is not sent to AInvasion’s servers. The quiz does not email you results.
1. AI Cost Calculator
What it does: Converts your monthly input and output token volume into a dollar figure for Claude, GPT-5.6, and Gemini models. It uses rate cards taken from each provider’s own pricing page, and it lets you toggle batch processing and prompt-cache hit rate.
Why those two toggles matter: They move the bill more than switching between similarly priced models usually does. Here is a worked example with hypothetical rates, chosen only to show the mechanics. Substitute real rates from the calculator.
Worked example (illustrative numbers, not a real price list)
Assumed rates: $3 per 1M input tokens, $15 per 1M output tokens.
Workload: 10,000 requests a month, 2,000 input tokens and 500 output tokens each.
Scenario Input cost Output cost Total Baseline $60.00 $75.00 $135.00 Batch at an assumed 50% discount $30.00 $37.50 $67.50 Caching: 1,500 of the 2,000 input tokens are a static prefix, 90% hit rate, and cache reads at an assumed 10% of base price. ≈ $23.55 $75.00 ≈ $98.55 The caching row ignores any cache-write surcharge, so a real bill would run slightly higher.
The takeaway most people miss: after caching, output tokens made up about 76% of the bill ($75 of roughly $98.55). Once your prompts have a stable prefix, input optimization hits diminishing returns, and the lever that remains is output length. Constrain response length, and avoid regenerating long answers.
Use it when you already know your traffic or can estimate it from logs.
Limitation: a calculator can only be as accurate as your volume estimate. Rate cards also change. The tool prints a verification date, so check it before budgeting.
Open the cost calculator →
2. AI Model Matrix
What it does: A sortable, filterable table of current Claude, GPT-5.6, and Gemini tiers (10 models in total) comparing price, context window, modality, and release date. You can filter by provider, price tier, or minimum context window.
How to use it well:
- Filter by hard constraints first. If you need to process 300-page documents, filter by minimum context window before you look at price.
- Shortlist two or three models, not one.
- Then test them on your own tasks. A spec table cannot tell you how a model handles your data.
Warning: Context window size is a ceiling, not a quality guarantee. A model that accepts a very long input may still retrieve details from it less reliably than from a short one. Treat the matrix as a way to rule models out, not to crown a winner.
Use it when: you are early in selection and want to cut the field quickly.
Open the model matrix →
3. Prompt Token Estimator
What it does: You paste a prompt and get a token-count range plus a live cost comparison across eight current models. It has separate presets for prose, code, and CJK/non-Latin text.
Why a range is the honest answer: Claude, GPT, and Gemini each use their own tokenizer, so the same text produces different token counts on different models. Any tool that gives one exact number without running each vendor’s tokenizer is implying precision it doesn’t have. A range reflects that uncertainty, and it is what you should expect from a browser-based estimator.
Why the presets matter: Token efficiency varies by content type. Code and non-Latin scripts typically consume more tokens per character than plain English prose, so a prose-based guess can badly underestimate a prompt in Japanese or a block of source code.
Tip: Estimate with the range’s upper bound when budgeting, and compare against the usage figures your provider returns in API responses. Those are the authoritative counts.
Use it when: you are about to send a long or expensive prompt and want a cost check first.
Open the token estimator →
4. Decision Quiz
What it does: Three questions on your task, budget, and technical comfort are matched against a fixed, published set of rules. You get two or three tools worth trying, and nothing is emailed to you.
What sets it apart: The matching is rule-based and published, so you can see why you got a result. It does not funnel you toward a sponsor. That is a design claim by AInvasion, and it is the right standard to hold any recommendation quiz to: if a quiz hides its logic, assume the logic includes a commercial incentive.
Use it when you are non-technical or simply don’t know where to begin.
Take the decision quiz →
5. AI Glossary
What it does: A searchable, alphabetized glossary of 70+ AI and LLM terms. It runs from foundations (tokens, transformers) to newer vocabulary (context engineering, agentic loops). Each entry is defined in plain English and has its own link, so you can send someone a specific definition.
Where it earns its keep: Cost conversations go wrong when two people use “context window” or “RAG” to mean different things. A shared definition you can link to takes thirty seconds and prevents a meeting.
Open the glossary →
Which tool should you use?
| If you want to… | Use this |
|---|---|
| Estimate a monthly bill from traffic you already know. | AI Cost Calculator |
| Shortlist models by price, context, and modality | AI Model Matrix |
| Learn what one specific prompt will cost. | Prompt Token Estimator |
| Get a straight answer when you don’t know where to start. | Decision Quiz |
| Understand a term like “RAG” or “context window.” | AI Glossary |
A workflow that works
- Quiz or glossary if the vocabulary or options are unfamiliar.
- Matrix, to cut the field to a short list.
- Token Estimator, on one real prompt per candidate.
- Cost Calculator, on your projected volume, with batch and cache toggled on and off to see the range.
- Re-verify prices on the provider’s pricing page before committing, since rates change.
Mistakes these tools help you avoid
- Budgeting from the input price alone. Output tokens are usually priced higher per token, and in the example above they dominated the bill.
- Comparing models on one token count. Tokenizers differ, so the same prompt is not the same size everywhere.
- Ignoring caching. If a large part of every prompt is identical, a high hit rate can cut input cost sharply.
- Sending latency-tolerant work to the real-time API. Reports, backfills, and bulk classification are candidates for batch pricing, if your provider offers it.
- Trusting a stale rate card. Check the date stamp.
Frequently asked questions
Are these tools really free, with no account?
Yes. According to AInvasion, all five work without sign-up, email capture, or login. The calculators and the matrix compute in your browser.
How current is the pricing?
Rates are checked against Anthropic’s, OpenAI’s, and Google’s pricing pages, and each tool prints its verification date. Because provider pricing changes often, rely on that date rather than on when the tool launched.
Do the Cost Calculator and Token Estimator give the same number?
No, because they answer different questions. The Cost Calculator projects a monthly bill from volume you already know. The Token Estimator starts from one pasted prompt and tells you what that text will cost.
I’m not technical. Is this useful to me?
Yes. Start with the Decision Quiz or the Glossary. Both are written for first-time tool choosers.
Can I trust a token estimate for billing?
Use it for planning only. Your provider’s usage report is the billing source of truth.
Methodology and limits
This article is based on the descriptions of the five tools provided by AInvasion. The worked example uses hypothetical prices and is labeled as such. No claim here comes from independent testing of the tools or from a live check of provider pricing. Before relying on any figure, confirm it against the tool’s own date stamp and the provider’s official pricing page.