foundations · Level 1
Which AI model should I use right now? A living, refreshed comparison
A refreshed, simpler edition of the six things worth weighing before you pick an AI assistant or model, built to outlast any single leaderboard.

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Start with the essentials
The short answer
There is no single best AI model, and any ranked list goes stale within weeks. Instead weigh six things on your own tasks: reasoning ability, effort to a usable result, context length, multimodal support, latency and data handling. Test two or three candidates on real work, check each factor against what you actually need, and keep a short log so your choice stays current as models change.
What you will learn
- You will be able to name the six factors worth weighing before choosing an AI assistant or model.
- You will be able to judge reasoning ability on your own tasks rather than trusting a headline claim.
- You will be able to test context length and multimodal support against files you actually use.
- You will be able to check latency and a service's data handling terms before you rely on it.
- You will have a simple model log and a rule for when to test again.
Who it is for
Anyone who already uses a chatbot and wants a clear, current way to choose between AI assistants or models, without chasing a leaderboard that will be out of date by next month. No coding needed.
Before you start
- Some experience of using a chatbot. What is AI and Your first prompts are ideal preparation.
Learn in your browser · Chapter 01 of 05
Six things to weigh, not one best answer
Any list that names a single 'best' AI model is out of date almost as soon as it is published. What does not go stale is knowing what to weigh, and knowing how to test the first and most important factor, reasoning ability, on your own work.
New models and updates arrive most months, so a ranked top five written today can read strangely within weeks. A short list of factors, and a habit of testing them yourself, keeps working long after any single article stops being current.
Scroll sideways to see every column.
| Factor | What it actually means | Ask yourself |
|---|---|---|
| Reasoning ability | How well it thinks through your kind of problem, not a general IQ score | Does it get MY tasks right, in a form I can use? |
| Effort to a usable result | How much back-and-forth it takes to get something you can use, not how polished the first reply looks | How many attempts or edits before an answer is actually usable? |
| Context length | How much text it can hold in mind at once | Can it find a detail buried in my longest real document? |
| Multimodal support | Whether it can work with images, PDFs, audio or spreadsheets | Does it accept the exact file types I actually use? |
| Latency | How long you wait for a reply | Is that wait fine at the time of day I actually work? |
| Data handling | Where your text goes, and what happens to it | Can I check and control that, and is it fine for this task? |
Start with reasoning ability, because it decides whether the other five factors are even worth weighing. A fast, cheap, private answer that is wrong is still wrong. A simple way to judge it: ask a question from your own field that contains a small false assumption, and see whether the assistant notices and corrects it, or simply goes along with it.
Try it yourself · Activity 01
15 minRun a three question reasoning check
Test reasoning ability on your own work before you look at anything else.
- Pick two AI assistants or models you already have access to.
- Write three questions: a real task from your own work, a question from your field with a small false assumption built in, and a small problem whose correct answer you already know.
- Ask all three questions to each candidate, using the same wording.
- Mark each answer plainly usable, usable with correction, or not usable, rather than scoring out of ten.
Did the two candidates land in the same place, or did one clearly notice things the other missed? Keep that answer in mind for the rest of this workbook.
Learn in your browser · Chapter 02 of 05
Effort: how much back-and-forth before you get something usable
How assistants are packaged and offered changes often, so a specific comparison written here would be out of date fast. What lasts is a way of thinking about effort that does not depend on today's set-up.
Different assistants offer different ways to work: some through a simple chat window, others through a developer interface for building your own tools. What is available, and how it is offered to you, changes often and without much notice, so always check what is currently on offer on the day you decide, rather than trusting what you remember from a few months back.
The thing that actually matters is effort per useful result, not how polished the first reply looks. An option that reads well but needs three attempts, heavy editing, or a fact check every time, can end up taking more of your time than an option that is a little slower to set up but gets it right on the first try.
A slicker-looking assistant is not automatically the one that saves you the most time, and it is not automatically the most private one either, which the next chapters cover. For now, treat effort as one weight among six, not the deciding factor on its own.
Try it yourself · Activity 02
10 minWeigh effort against reasoning for one task
Take the real task you used in the last chapter's check and think about effort honestly.
- Note how you accessed each candidate for this task.
- Estimate how many attempts each candidate needed to give you a usable answer to your real task.
- Decide which candidate actually took you less time and effort, not which one gave the most polished-looking first answer.
Would your answer change if the task mattered more, such as something you would be embarrassed to get wrong?
Learn in your browser · Chapter 03 of 05
Context length and multimodal support: what it can hold, and what it can read
These are two of the most oversold specifications in AI marketing. A long context window looks impressive on a page. Whether it is actually used well, and whether your files are even accepted, are separate questions worth testing yourself.
The context window is how much text an assistant can consider at once, including your messages, its replies and any documents you add. A longer window helps with big documents, but a detail buried in the middle of a long file can still be missed even when the window is technically large enough to hold it. A big number on a spec page is not the same as reliable recall.
Multimodal support means an assistant can work with more than plain text: images, PDFs, audio or spreadsheets. Claims here vary a great deal between assistants and between different versions of the same assistant, so check the exact file types you actually use rather than trusting the word 'multimodal' on its own.
Scroll sideways to see every column.
| File type you use | A quick test |
|---|---|
| A long document you know well | Ask about a detail from the middle, not the start or end |
| An image | Upload one and ask a specific question about it, not just 'describe this' |
| A PDF with tables | Ask it to pull out one exact figure or row |
| A spreadsheet | Ask a question that needs it to look across several rows or columns |
| Audio | Check whether it accepts audio at all before you rely on it |
Try it yourself · Activity 03
20 minStress test the two specs that get oversold
Test context length and multimodal support on files you actually use, not a demo.
- Choose the longest document you know well, paste or upload it, and ask about a specific detail from somewhere in the middle.
- Choose one file type you genuinely use for work, such as an image, PDF or spreadsheet, and check whether your candidate accepts it before testing it properly.
- Note anything it missed, invented, or simply could not accept.
Did the result match what the spec page claimed, or was there a gap between the headline claim and what actually happened?
Learn in your browser · Chapter 04 of 05
Latency and data handling: speed you can live with, and where your text goes
These two are easy to forget about until something goes wrong: how long you actually wait for a reply, and what happens to what you typed once you send it.
Latency is how long you wait for a reply. It is not fixed: a request that needs more reasoning usually takes longer by design, and speed can vary by time of day if a service is under heavy load. Test it at the times you actually work, not once, first thing, when everything is quiet.
Data handling is where your text goes and what is done with it. Do not assume a service is private just because it feels convenient or well designed. Before you paste anything, check whether your conversations may be used to improve the service, and whether you can switch that off in your settings.
Scroll sideways to see every column.
| Question to ask | Where to find the answer |
|---|---|
| What is kept, and for how long? | The service's privacy or data policy |
| Is it used to train or improve the model? | The privacy policy, and your account's data controls |
| Can I turn that off? | Your account settings, usually under privacy or data controls |
| Who else can see it? | The privacy policy's section on sharing and third parties |
If a task is genuinely confidential, that is usually a sign to slow down rather than to test quickly: read the actual privacy terms, ask your employer's policy if one exists, and consider whether a model you run yourself is more appropriate. That deeper comparison, including self-run open-weight models, is covered fully in this library's original model-comparison workbook.
Try it yourself · Activity 04
10 minCheck the privacy setting before you test anything else
Read the actual setting rather than assuming you know what it says.
- Open the current privacy or data settings for one assistant you use regularly.
- Write down, in your own words, whether your chats may be used to improve the service.
- Write down whether you can switch that off, and whether you have already done so.
Did the setting say what you expected, or did anything surprise you?
Learn in your browser · Chapter 05 of 05
Put the six together, and keep a living decision
One factor rarely decides alone. This closing chapter turns the six into a single weighing exercise, then shows you the habit that keeps any choice from going stale: a short model log.
Different tasks put weight on different factors. A confidential document puts data handling first. A quick brainstorm puts latency and effort first. A long report puts context length and reasoning ability first. Decide your top two or three factors for a task before you compare anything, or the most impressive-sounding feature will decide for you.
A model log is a short, honest record of what you tested, when, and what you decided. It stops you repeating work you have already done, and it shows you clearly when an old decision has gone stale.
Scroll sideways to see every column.
| Date | Task | Candidate and access route | Reasoning check | Attempts needed | Context and files tested | Latency note | Privacy checked | Decision |
|---|---|---|---|---|---|---|---|---|
| Example | Weekly report | Candidate A, chat app | Usable | 1 attempt | Held a 12 page document | Fine at 9am | Setting checked, off | Keep for this task |
Try it yourself · Activity 05
15 minStart your own model log
Turn today's testing into a record you will actually keep.
- Create a simple page or spreadsheet using the columns from the table above.
- Add one row for the task and candidate you tested in this workbook's exercises.
- Write down your current decision, and the date or trigger that will make you test again.
What would actually make you switch to a different assistant or model? Write that trigger down now, so you notice it when it happens.
What you can do now. You have six factors to weigh instead of one brand to chase, a small test for each one, and a log that keeps your decision current without you needing to track every new release yourself.
Keep this workbook. It is yours to keep, print and write in. Come back to it whenever a new model launches, your work changes, or your current choice starts to feel wrong.
https://trust-agent.ai/exam/which-ai-modelThis is free educational content published by Mickai LTD, not professional, legal, financial or compliance advice, and Mickai accepts no liability for how it's used.
Trust Agent publishes workbooks like this one for free because a framework you can apply yourself, kept current by your own testing, is worth more than any single ranked list ever could be.
Keep learning
The complete workbook
This is a refreshed, simpler edition of Trust Agent's model-comparison workbook. Rather than naming a winner, it gives you six factors to weigh for any AI assistant or model, in plain language, with a small test for each one. You will finish with a short decision log you can keep using long after today's names have changed.
- 01Six things to weigh, not one best answerRead here · 1 exercise
Any list that names a single 'best' AI model is out of date almost as soon as it is published. What does not go stale is knowing what to weigh, and knowing how to test the first and most important factor, reasoning ability, on your own work.
- 02Effort: how much back-and-forth before you get something usableRead here · 1 exercise
How assistants are packaged and offered changes often, so a specific comparison written here would be out of date fast. What lasts is a way of thinking about effort that does not depend on today's set-up.
- 03Context length and multimodal support: what it can hold, and what it can readRead here · 1 exercise
These are two of the most oversold specifications in AI marketing. A long context window looks impressive on a page. Whether it is actually used well, and whether your files are even accepted, are separate questions worth testing yourself.
- 04Latency and data handling: speed you can live with, and where your text goesRead here · 1 exercise
These two are easy to forget about until something goes wrong: how long you actually wait for a reply, and what happens to what you typed once you send it.
- 05Put the six together, and keep a living decisionRead here · 1 exercise
One factor rarely decides alone. This closing chapter turns the six into a single weighing exercise, then shows you the habit that keeps any choice from going stale: a short model log.
Also inside: a 8-point checklist, a glossary of 10 terms and 11 questions and answers to test yourself. 5 hands-on exercises, each with a worked answer at the back where the workbook gives one.
The PDF is free. We ask for your name and email before downloading. Read the privacy notice at the download form. Free to download and use for personal learning, study groups and inside your own team. Please do not resell the workbooks or republish them as your own. Link people to trust-agent.ai instead.
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Test yourself
Questions and answers
Which AI model is the best one to use?
There is no single best model for everyone. The right choice depends on your task, and on how you weigh reasoning ability, effort to a usable result, context length, multimodal support, latency and data handling for that specific task. Test two or three candidates on your own work rather than trusting a ranked list.
How do I judge an AI model's reasoning ability myself?
Ask it a real task from your own work, a question from your field containing a small false assumption, and a problem you already know the answer to. Mark each reply plainly usable, usable with correction, or not usable, rather than trusting a general score.
Is a more polished-looking AI reply always the better one?
Not necessarily. What matters is effort per useful result. An option that reads well but needs several attempts or heavy correction can end up taking more of your time than an option that takes a little longer to set up but is right on the first try.
Why does the way AI assistants are offered keep changing?
Providers regularly change interfaces, access routes and what is bundled together, often without much notice. Always check what is currently on offer on the day you decide, rather than relying on what you remember from a previous month.
Does a longer context window mean better answers?
Not on its own. A longer window lets a model take in more text at once, which helps with big documents, but a detail buried in the middle can still be missed. Test with a document you know well, not just the headline number.
What does multimodal actually mean, and can I trust the label?
Multimodal means an assistant can work with more than plain text, such as images, PDFs, audio or spreadsheets. Support varies between assistants and between different versions of the same assistant, so test the exact file type you use rather than trusting the word on its own.
Why does an AI assistant sometimes feel slow?
A reply that needs more reasoning usually takes longer by design, and speed can also vary with how busy the service is at that time of day. Test latency at the times you actually work, not just once when things are quiet.
Is a well-known AI tool automatically more private than a lesser-known one?
Not automatically, but you should never assume either way. Check the actual privacy or data setting, in your own words, for whether your chats may be used to improve the service and whether you can turn that off.
What should I do before pasting confidential material into an AI tool?
Slow down. Read the actual privacy terms, follow your employer's policy if one exists, and consider whether a model you run yourself is more appropriate. Never paste passwords or other people's private details into any AI tool while testing.
How often should I re-test my choice of AI model?
Re-test when a candidate releases something new, when a plan or its terms change, when answers start to feel worse, or when your own work changes. Otherwise, checking in every few months is a sensible habit. A model log shows you when you last looked.
How do I stop my choice of AI model going stale as new ones launch?
Keep a short model log: what you tested, when, and what you decided, plus the trigger that will make you test again, such as a new release or a change to a plan's terms. That habit, not any single ranked list, is what keeps your choice current over time.
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Review your work
Work through the exercises and questions, then compare your reasoning with the worked answers. A scored exam and verifiable certificate are not yet available for this course.
Review the questionsLearn the language
Key terms
- Model
- The trained engine that turns your input into a reply. Different assistants can use the same model, and one assistant can offer several.
- Assistant
- The finished AI product built around a model, including its interface, hidden instructions, memory and safety filters.
- Reasoning ability
- How well a model thinks through a problem in your kind of task, best judged on your own real questions rather than a general score.
- Context window
- The amount of text a model can take into account at one time, including your messages, its replies and any documents you add.
- Multimodal
- Able to work with more than plain text, such as images, PDFs, audio or spreadsheets.
- Latency
- How long you wait between sending a message and receiving a reply.
6 of the workbook's 10 terms. The complete glossary is in the workbook.
Follow the evidence
Sources and checks
Facts last checked: .
These workbooks use AI assistance. See how the workbooks are made.
- Claude by AnthropicAnthropic
- Gemini, your AI assistant from GoogleGoogle
- ChatGPT release notesOpenAI Help Center
Created by Mickarle Wagstaff-Irons - Micky Irons with the Mickai team. Published by Mickai LTD. Last updated 29 September 2026.
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