How to use multiple AI models in one place

Using multiple AI models in one place is no longer an expert setup. It's the logical next step after a first month of practice, when you discover that each model family has its own strengths and that exclusive loyalty to a single provider costs a lot. Three routes lead there, from the simplest to the most technical. Once you've picked one, you can compare the models themselves side by side on your own everyday tasks.

One distinction comes first, to avoid the industry's usual commercial misunderstanding. Subscription aggregators sell access to several models inside their plan. The BYOK route plugs YOUR keys into ONE tool. Both exist and both can be defended. The second gets the full treatment, with every token paid at the provider's list price and nothing added on top.

01Key takeaways

• There are three routes to multi-model access. A multi-key BYOK app, a single-key gateway and an abstraction layer for developers.
• For users who don't code, the multi-key app is enough. You add one key per provider and switch from a menu.
• A side-by-side comparison on your own tasks replaces every forum debate about "the best model".
• Using multiple models removes dependence on a single provider. The day a price list changes, you move in one click.
• Local models round out the picture for offline work and maximum privacy.

02Why use several models in one place

Model families don't excel at the same things. One provider shines at careful writing, another at floor prices and a third at giant contexts or sourced research. Locking yourself into a single provider means accepting its weaknesses along with its strengths. AI without a subscription argues for exactly the opposite, which is the freedom to take the best of each.

The "one place" matters as much as the "several". Three models in three tabs with three histories guarantee a scattered mess. Gathered in a single tool, they share your templates, your habits and your tracking, so changing engines becomes a dropdown menu instead of moving tools and histories. It's also the best insurance against dependence. The day a price list goes up or a model declines, leaving takes one click.

03Three approaches, from simplest to most technical

Approach	Who it suits	Distinctive feature
Multi-key BYOK app	everyone, zero code	your keys, direct list prices, switch from a menu
Gateway (OpenRouter)	anyone who wants a single key	hundreds of models, pass-through fees
Abstraction layer (LiteLLM)	developers	one code interface for all providers

A fourth family exists, the subscription aggregator, which includes the models in its plan. It's a different business model, where usage goes through the aggregator's terms instead of your own keys. Choosing between the two philosophies mirrors the choice behind the whole BYOK approach. Each person can judge with their own volumes and their own transparency standards, calculator in hand.

04The multi-key BYOK app, the no-code route

The principle fits in one sentence. The application accepts one key per provider. Each tool or conversation picks its model from a menu. You create your keys at OpenAI, Anthropic, Mistral or elsewhere depending on your needs. You paste them once into the settings and the setup is done for good. Creating each of your keys takes five minutes per provider.

OpenTahr works this way and the account is free. Several keys are stored in your browser, each tool has its model menu and you switch in one click in the Expert Chat as well as in the article generator. The consumption of each key stays visible at its provider, at list price, with no billing intermediary. You get multiple models without a single line of code and without any in-house credits between you and the price lists.

05The gateway puts every model behind one key

OpenRouter flips the assembly around. You get one account and one key. Behind it sit hundreds of models from every provider, billed as they pass through with a service margin. The appeal is twofold. Your inventory gets simpler, with one key to protect instead of five. You also get immediate access to new releases. The price is a slight extra cost plus one more intermediary in the chain.

The OpenRouter key guide details account creation and the exact fees. The typical good use is the explorer who wants to taste many models before settling on choices. That person then keeps the gateway for the long tail and takes direct keys at their two or three main providers, which gives them the best of both worlds.

06The abstraction layer is a developer tool

For people who code their own applications, libraries such as LiteLLM expose every provider behind a single programming interface. The same call works with the OpenAI key or the Anthropic key. Changing models becomes a parameter. The publisher claims support for more than a hundred models and substantial savings in management code. Those figures are the publisher's own, while the technical principle is solid and proven.

It's the technical equivalent of the multi-key app, in workshop form. You get the same keys and the same freedom, with maintenance on top. If you don't develop software, this route doesn't concern you. It still deserves a mention to show what ready-made tools do for you under the hood.

07The starter pair, a flagship and a floor model

The first useful multi-model setup takes two keys, with a reference model for quality and a budget model for volume. On one side sits the flagship or mid-tier model from OpenAI or Anthropic. On the other sits a floor model such as DeepSeek or a small Mistral, ten to fifty times cheaper on output depending on the price lists. Drafts, sorting and rephrasing go to the floor model, while final texts and sensitive analyses go up to the reference.

This pair covers the vast majority of individual needs and gives you material for comparisons along the way. Each time a task hesitates between the two tiers, a side-by-side test settles it in a minute. It also settles the eternal question of the chat plan. Many people keep their chat subscription for open discussion and hand production to the key pair. The figures for both sides of that trade-off are in the plan versus key match. The pairs then adjust to your profile, with sourced research as a third key for some people and images for others. The pair remains the foundation.

08Keep the setup readable with caps and statements per key

Using multiple models has a single enemy, which is mess. Three habits keep it away. The first is a spending cap per key, set at creation at each provider so that experimenting never turns into a surprise. Then comes naming keys by tool or by use, so every statement can be read without straining your memory.

Last comes a single monthly appointment. You open the providers' usage pages side by side and spend five minutes checking that each key spends what you expect of it. Three providers don't demand three times more management. They demand the same simple discipline applied three times. Once it's well organized, it fits into a monthly quarter of an hour.

09The traps of using multiple models

The collector comes first. Opening six accounts in the first week scatters your learning and guarantees five orphaned keys to revoke later. The second key waits for the real use that calls for it. The third one waits too. The comparer without a grading grid comes next. Judging two answers on the impression of the moment favors style over accuracy, while three criteria written in advance are enough to make the verdict honest and repeatable.

The last trap is the overly specific template. Instructions packed with tricks specific to one model travel badly to the others. Write your roles and instructions in clear plain language, portable by design. Handle each provider's quirks in the tool's settings instead of the role text. Three traps come with three simple fixes. None of these traps justifies giving up the freedom the setup brings.

10Comparing answers side by side, the real reward

Multiple models are not just for switching. They also tell you things. You send the same instruction to two models, see both answers in front of you and give your verdict on YOUR criteria. That's the blind test protocol applied to daily work. The blind comparison protocol formalizes it for big decisions, while the quick version lives in everyday use with two tabs and one minute.

The discoveries always surprise. A budget model might match the flagship on your rephrasing, the provider known for code might also win your summaries and a difference in tone might settle weeks of hesitation on its own. Write these verdicts down with their date. They feed task-by-task routing, the art of paying for each job at the tier that's enough, a neighboring topic that complements this one.

11What a month with multiple models looks like

In practice, the week of a creator equipped with the pair looks like this. Article outlines and rephrasing run on the floor model for a few cents a week. Final versions go through the reference model for a few dozen cents more. A pointed question goes once or twice to the research model. No mental gymnastics are needed, because the default model of each tool does the sorting on its own, set once and for all.

On the monthly statement you find three small lines at three providers. Their sum stays well below what all-flagship usage would have cost. The occasional switching has also produced verdicts. Two tasks moved down a tier with no loss observed, while one moved back up for good reasons. The setup lives, adjusts and documents its own choices week after week. That's the daily routine the three steps further down put in place.

12Where local models fit in the picture

The local family, with LM Studio, Jan or Ollama, runs open models directly on your machine. There's no key, no provider and no data leaving your computer. You pay the price elsewhere, in serious hardware and in quality that is generally lower than the big hosted models on demanding tasks. For offline drafts or absolute privacy, though, this option has its full place in a multi-model toolkit.

Nothing forces you to pick a side. Many advanced users keep a small local model for sensitive material and their keys for serious work. The spirit stays the same as in the whole approach. The right tool for each task beats a single tool chosen on principle or out of laziness about taking stock.

13Getting started without code in three steps

1. Start with one key, the one for your dominant need. Choosing your first key settles it in five questions.
2. Add the second one when a real use calls for it, such as floor prices, sourced research or images. Paste it into the same tool.
3. Compare side by side on three tasks, note the verdicts and then set the default model of each tool accordingly.

With three steps spread over a month, the multi-model setup is in place and working for you. An assistant set up on your key keeps its role whatever the engine, while the price lists side by side guide your trade-offs as new models come out. Variety isn't a complication. Well organized, it becomes an everyday freedom you steer from a dropdown menu.

14Frequently asked questions

Can I use ChatGPT, Claude and Gemini in one place?

Yes, through three routes. You can use a BYOK application that accepts one key per provider or a gateway like OpenRouter that serves them behind a single key. Developers can also use an abstraction layer like LiteLLM. The first route needs no code, since you paste your keys once and then switch from the menu, conversation by conversation.

What is OpenRouter?

It's a gateway, meaning a single account and key that give access to hundreds of models from every provider, billed as they pass through with a service margin. It's handy for exploring widely or simplifying your key inventory. The exact fees and the account setup are detailed in the dedicated OpenRouter guide.

Does using multiple models cost more?

It doesn't. The opposite is closer to the truth. Each key only bills its real consumption, so having three keys with two of them idle costs strictly nothing in a month. The gain comes from choice, with each task sent to the model that offers it the best value. Total spending usually drops once routing becomes a habit.

Do I need several subscriptions for several AIs?

Not on the BYOK route. None of the models requires a subscription, since each key is prepaid and charged by usage. The only possible plan is the one for the tool that hosts your keys, fixed and known in advance. Subscription aggregators follow a different business model, which you can compare with full knowledge of the facts.

Transparency note. The capabilities claimed by the tools cited, such as the number of supported models or savings in code, come from their publishers and are attributed as such. Gateway pass-through fees can be checked on their official pages. No tool or provider mentioned pays us anything.

15Sources

1. OpenRouter, official gateway documentation
2. LiteLLM, official documentation of the abstraction layer
3. Ollama, official site (local models)