How to Use Local AI on Your Own Files

Coding Liquids blog cover featuring Sagnik Bhattacharya for using local AI on your own files.
Coding Liquids blog cover featuring Sagnik Bhattacharya for using local AI on your own files.
This is the task recipes post — summarise, extract, classify local files. Model-agnostic: works with Gemma, Llama, Mistral, or any local model. For install + hardware, see run Gemma 4 on your own machine.

You have files — documents, code, spreadsheets, notes — that you want AI to help with. But you do not want to upload them to ChatGPT, Claude, or any other cloud service.

With a local AI model, you can process those files on your own machine. This guide covers the practical setup and common file-processing tasks you can do locally.

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Quick answer

Run a local model with Ollama, then write a simple script that reads your files, sends them to the local model with a specific prompt, and saves the results. Common tasks include summarisation, extraction, classification, and search.

  • You have sensitive files that cannot be uploaded to cloud AI services.
  • You want to batch-process files without per-token API costs.
  • You need AI assistance with files while working offline.
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Setting up for file processing

Install Ollama and pull a model (Gemma 4 12B is a good balance of quality and speed). The model runs as a local service you can call from any script.

For file processing, you mainly interact through the API rather than the chat interface — you need to programmatically read files, send them to the model, and collect results.

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Common file tasks

The most useful local AI file tasks fall into a few categories: understanding what files contain, extracting specific information, transforming content, and finding patterns across multiple files.

  • Summarise documents — get key points from long reports or articles
  • Extract structured data — pull names, dates, amounts from unstructured text
  • Classify files — tag documents by topic, priority, or category
  • Search semantically — find files related to a concept, not just a keyword
  • Generate descriptions — create metadata or alt text for files
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Handling different file types

Text files work directly. For PDFs, use a library like PyMuPDF or pdfplumber to extract text first. For Word documents, use python-docx. For spreadsheets, use openpyxl or pandas.

The pattern is always the same: extract the text content, send it to the model with your prompt, and process the response.

import fitz  # PyMuPDF
import requests

def process_pdf(pdf_path: str, prompt: str) -> str:
    # Extract text from PDF
    doc = fitz.open(pdf_path)
    text = "\n".join(page.get_text() for page in doc)
    # Send to local model
    response = requests.post("http://localhost:11434/api/generate",
        json={"model": "gemma3", "prompt": f"{prompt}\n\n{text}",
              "stream": False})
    return response.json()["response"]

Batch processing patterns

For processing many files, use a simple loop with progress tracking. Save results to a CSV or JSON file so you do not lose work if the script is interrupted.

Consider processing files in parallel if your hardware can handle it — but watch memory usage with larger models.

Working with large files

Local models have context window limits. If a file is too large to fit in a single prompt, split it into chunks and process each chunk separately. Then use a final prompt to combine the chunk results.

For very large documents, consider extracting only the relevant sections (headings, specific pages, key paragraphs) rather than sending the entire content.

Worked example: processing a folder of meeting notes

You have 30 meeting note files in a folder. A script sends each one to local Gemma 4 with the prompt 'Extract all action items with assigned owners and deadlines.' The script saves the results to a CSV. Total time: 10 minutes. Total data uploaded to the cloud: zero.

Common mistakes

  • Sending files larger than the model's context window without splitting.
  • Not saving intermediate results — if the script crashes halfway through, you lose everything.
  • Using the chat interface instead of the API for batch work.

When to use something else

If you want to build a full RAG system over your documents, see building a RAG app. For setting up the local model itself, see running Gemma 4 on your own machine.

How to apply this in a real AI project

How to Use Local AI on Your Own Files becomes much more useful once it is tied to the rest of the workflow around it. In real work, the result depends on model selection, prompt design, tool integration, evaluation, and the operational reality of shipping AI features, not only on following one local tip correctly.

That is why the biggest win rarely comes from one clever move in isolation. It comes from making the surrounding process easier to review, easier to repeat, and easier to hand over when another person inherits the workbook or codebase later.

  • Test with realistic inputs before shipping, not just the examples that inspired the idea.
  • Keep the human review step visible so the workflow stays trustworthy as it scales.
  • Measure what matters for your use case instead of relying on general benchmarks.

How to extend the workflow after this guide

Once the core technique works, the next leverage usually comes from standardising it. That might mean naming inputs more clearly, keeping one review checklist, or pairing this page with neighbouring guides so the process becomes repeatable rather than person-dependent.

The follow-on guides below are the most natural next steps from How to Use Local AI on Your Own Files. They help move the reader from one useful page into a stronger connected system.

Related guides on this site

These guides cover local model setup, RAG systems, and private AI patterns.

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