Gemini AI complete tutorial, 2026 Google large model zero-based guide

Gemini is a large multi-modal model launched by Google. It is positioned as a direct competitor of ChatGPT and Claude. It has its own differentiated advantages in search integration, long context, video and code understanding. Gemini in 2026 has become the backup or even the main AI assistant for many users. However, because the product line, entrance, subscription level and API calls are relatively scattered, novices often cannot figure out the way when they first contact it. This article writes a complete usage tutorial from a zero-based perspective, breaking down Gemini’s entry barrier into operable steps, covering account registration, product entry, conversation skills, image and video code scenarios, subscription levels, and API calls, so that users who have never used Google AI can get started with the system within half an hour.

1 What Gemini is and is not

Gemini is a large language model developed by Google DeepMind. Its predecessor can be traced back to the Bard and PaLM series. Unlike ChatGPT, Gemini has deeply integrated multi-modal capabilities from the beginning. Text, images, audio and video are all natively supported, rather than added later through plug-ins.

Nor is it the entirety of Google’s AI strategy. Google also has models within Google that specialize in search AI Overview, models that specialize in translation, and Veo that specializes in video generation. Gemini is a universal conversation product for developers and end users. The core entrances are the gemini.google.com web version and the Gemini mobile App. Developers use the Gemini API on Vertex AI and Google AI Studio more.

2 How to register and log in to Gemini

Gemini requires a Google account. If you are already using Gmail or YouTube, just log in with your existing account. Visit gemini.google.com, click on the upper right corner to log in, select your Google account to enter the conversation interface.

Region restrictions are the most common problem for newbies. Gemini is not available in mainland China by default and requires an overseas IP to access. A Google account must also be an account in a supported region. Hong Kong, Singapore, North America, Europe, Japan, and South Korea basically all support it, and you can use it by logging in directly. Mobile Apps are available on the App Store and Play Store. App Store requires an overseas account to download, and the same applies to Play Store. If it is just a temporary trial, the threshold for the web version is lower.

3 Core interactions of Gemini web version

After entering gemini.google.com, the interface is very simple, with a dialog box in the middle, an input box below, and a list of historical conversations on the left. You can directly enter the question in the input box, press Enter to send, and the model will start replying within a few seconds. Replies support text format rendering, code blocks come with a copy button, and long replies will be automatically segmented.

The input box supports uploading images, PDF and audio files. Just click the attachment icon to select the file. Gemini handles multi-modal input very naturally, allowing it to analyze a picture, summarize a PDF, and transcribe a piece of speech. The process is not essentially different from sending a text message. There are like and thumbs down buttons below each reply. After thumbs down, you can submit feedback to the Google team to optimize the model.

4 Gemini App mobile experience

The Gemini mobile app integrates some functions of Google Assistant and replaces the original Google Assistant on Android. After it is turned on, you can use your voice to directly summon it. You can ask about the weather, translation, or recipes. The response speed is much faster than traditional voice assistants.

The iOS version of Gemini App is slightly less functional because it cannot replace Siri's system integration and can only be used as a standalone App. But the core experience of dialogue is the same, and uploading and analysis of text, pictures, and videos are supported. Android users should set Gemini as their default assistant and long-press the power button to call it up. iOS users can add shortcuts to the home screen, and the experience is not bad.

5 Cue Words and Conversation Tips

Gemini eats prompt words like other large models. Asking the question directly will get you the answer, but adding some structured context can significantly improve the quality of the response. The most commonly used technique is to give it a role, such as writing a product description for me. Your identity is an e-commerce operation copywriter with ten years of experience. In this way, the model will be output in an expert tone, and the content depth will be increased.

Another tip is to take it apart step by step. If you ask too many questions about a complex task at one time, it is easy to miss the model. You can break it into several rounds of dialogue, first let it outline, then let it fill in each section, and finally let it unify the style. Gemini's context window is relatively long, and it can remember information within several rounds of conversations, making it suitable for such multi-step tasks.

If you find that the reply is not accurate enough, you can ask it to regenerate it several times or tell it clearly where it needs to be changed. If you directly say that this section is too wordy, please summarize it in three sentences, or if this part lacks specific examples, please add two real cases. The model will usually be adjusted immediately.

6 Use Gemini for long document processing

One of the core selling points of Gemini is the extremely long context window. The specific number of tokens supported varies by version, but it can actually feed complete PDF papers, several hours of video subtitles, and entire e-books. The model can summarize, answer questions, and rewrite within a round of dialogue. This capability is a qualitative leap compared to ChatGPT’s early 8K or 32K windows.

For practical usage, drag a 50-page PDF into the dialog box and let Gemini make an overall summary before answering your specific questions. Or upload a two-hour recording of a meeting and have it generate a summary of key decisions and a to-do list. The bottleneck of long document processing is not the model capability but how you ask questions. The more specific the questions, the more useful information you can get.

7 Use Gemini to process pictures and videos

Image understanding is Gemini’s strength. Upload a picture, and the model can identify objects, describe scenes, read text on the picture, and reason about relationships in the picture. Common uses include translating menus, taking pictures of whiteboards to convert content into text, identifying plants and animals, looking at pictures and writing poems, and analyzing tables and charts.

Video understanding is relatively new but already available. Upload a video or paste a YouTube link (if you have access), and Gemini can summarize the content, extract key time points, and answer questions about the video content. The processing time is directly proportional to the length of the video. Videos of several minutes are usually analyzed in more than ten seconds. The video function is more completely covered in the subscription version, and the free version may have a limited duration.

8. Writing code with Gemini

Gemini's coding capabilities will be close to the mainstream first-tier level in 2026. Write requirements directly on the web version, and the model will generate complete code with comments and usage examples. Common scenarios include writing gadget scripts, debugging error messages, interpreting other people's code, generating unit tests, and doing code reviews.

To make Gemini write code more accurately, there are several suggestions. The first is to clearly indicate the language version and framework, such as Python 3.11 plus FastAPI, and the model will use the corresponding syntax. The second is to paste the error message into the conversation as it is. Gemini can usually directly provide a repair plan after reading the error report. The third is to require it to self-review after writing, and the model will proactively point out possible boundary conditions or performance issues.

9 How to choose Gemini subscription level

Gemini has a free version and a paid version. The free version allows unlimited chat but accesses a smaller model and may not necessarily have the most stable response speed. The paid version has access to more powerful Pro or Ultra models, with deeper long context support, more accurate multi-modal processing, and open access to advanced functions such as video generation.

The specific pricing varies in different regions. It is usually bundled with Google’s One subscription, and some premium tiers are sold separately. The core criterion for deciding whether to pay is your frequency of use. If you use it more than a dozen times a day, need to process long documents or videos, and do serious coding work, the experience of the paid version is obviously different. Just talk about the free version occasionally.

10 How do developers access Gemini API?

Developers want to integrate Gemini into their own applications. The standard path is to use Google AI Studio or Vertex AI. AI Studio is a free start-up development environment. You can debug directly on the web page and get the API Key from the prompt. Vertex AI is an enterprise-level platform that integrates more enterprise-level functions such as quota management, private deployment, and linkage with other GCP services.

The access process is relatively simple, just register a Google Cloud account, enable the Gemini API, generate an API Key, and use Google's official SDK to call it in the code. The SDKs for Python and JavaScript are both mature, and Node, Go, and Java also have official support. It is recommended to start with simple text generation for the first call, and then add advanced features such as multi-modal input, streaming output, and tool calling after running through it.

11 How to match Gemini and ChatGPT

The actual workflow of many deep users is a mixture of Gemini and ChatGPT. Gemini has advantages in long documents, videos, pictures, and Google ecosystem integration. ChatGPT has a reputation for fine-tuning quality in custom GPTs, plug-in ecology, and specific vertical scenarios (legal, medical, and financial). Claude has a reputation for rigorous programming.

How to match it depends on the scene. When writing long papers, I tend to use Gemini to process a large number of reference materials and get abstracts, and then use ChatGPT or Claude to write the main text. When dealing with multimedia materials, I will use Gemini first. When writing code and doing development, I will give priority to using Claude or Cursor. You can customize a workflow for yourself every day without having to stick to one tool.

12 Frequently Asked Questions FAQ

Can Gemini be used in mainland China?

Officially unavailable by default. An overseas IP network environment and an overseas Google account are required for normal access. The mobile app requires an overseas App Store or Play Store account to download. If it is a temporary trial, it is recommended to start with the web version, as the threshold is lower than that of the app.

Is there a big difference between the free version and the paid version of Gemini?

The gap is mainly reflected in model version and function opening. The free version uses a medium-sized model, which is sufficient for daily conversations. The paid version is connected to Pro or Ultra, and the accuracy of processing long documents and multi-modal tasks is significantly higher. Advanced functions such as video generation are only available in the paid version. Ordinary users should try the free version for a week or two first, and then upgrade if they feel the bottleneck.

Will uploading files to Gemini reveal privacy?

Google's terms of service state that user-entered data may be used to improve the model, but there are dedicated enterprise and API version options to turn off the use of training data. During the use of ordinary consumers, the conversation history in the Google account can be manually deleted. When business secrets or personal sensitive information are involved, it is recommended to use the paid enterprise version or API call instead of the consumer version.

Gemini How about writing Chinese?

The overall Chinese expression is smooth, but compared to domestic models, it is a bit stiff in some colloquial scenes and the latest hot words. Gemini has no obvious shortcomings in scenarios such as professional writing, long texts, and technical translation. If you have high requirements for Chinese style, you can write more Chinese examples and feed them to it as a reference, and the model will imitate your tone.

Do Gemini API calls cost money?

Google AI Studio provides a free starting quota. There is basically no charge for calls within a few hundred times a day. If the quota is exceeded, tokens will be charged. Vertex AI adopts GCP standard billing, and the price is tiered based on the number of input and output tokens. The specific unit price is subject to Google's official pricing page. The monthly cost of small applications usually ranges from a few dollars to dozens of dollars.