Best Free AI Tools for Developers (July 2026)

Most "free AI tools" are free trials with a credit card wall. These aren't. Every tool on this list works right now in your browser. No signup. No API key. No 14-day countdown.

We built most of these because we needed them ourselves. Comparing model pricing across 200+ models shouldn't require a spreadsheet. Converting a CSV to JSON shouldn't require installing pandas. Here are the tools we use daily, organized by what they actually do.

Model Comparison and Selection

Benchmark Dashboard

Compare 200+ AI models on quality, speed, and price in one view. Data sourced from the Artificial Analysis Intelligence Index v4.1 and Coding Agent Index v1.1, updated when new models drop.

Filter by use case, sort by any metric, see which models sit on the cost-performance frontier. This is the tool we check first when a new model launches.

Try it: Benchmark Dashboard

Model Selector

Answer a few questions about your workload and get a personalized model recommendation. Factors in budget, task type, speed requirements, and context window needs.

Faster than scrolling through the benchmark dashboard when you just need a quick answer to "which model should I use for X?"

Try it: Model Selector

Cost Calculator

Estimate your monthly AI API costs for different model configurations. Plug in your task volume and token usage to compare setups.

We covered the cost optimization strategies in detail in our guide to reducing AI API costs. The calculator makes those estimates concrete.

Try it: Cost Calculator

Token Counter

Paste text and see exact token counts for different models. Helpful for estimating costs, staying within context limits, and understanding why some prompts cost more than others.

Different tokenizers produce different counts. A 1,000-word prompt might be 1,200 tokens with GPT-5.6 but 1,350 with Claude. The counter shows both.

Try it: Token Counter

Data Conversion Tools

Text to CSV Converter

Paste text, pick a delimiter, download a CSV file. Auto-detects tabs, commas, pipes, semicolons, and spaces. Runs entirely in your browser. Your data never leaves your machine.

Includes AI Smart Parse for messy data that doesn't follow a consistent delimiter pattern. We covered all five conversion methods in the text-to-csv guide.

Try it: Text to CSV

CSV to Text Converter

The reverse of the above. Take structured CSV data and convert it back to plain text with your choice of separator.

Try it: CSV to Text

CSV to JSON Converter

Upload CSV, get a valid JSON array of objects. Each CSV header becomes a JSON key. Handles quoted fields, mixed delimiters, and large files. We wrote a full guide on CSV to JSON conversion if you need batch or custom approaches.

Try it: CSV to JSON

JSON to CSV Converter

The reverse. Flatten JSON arrays into downloadable CSV files. Handles nested objects by creating dot-notation column headers.

Try it: JSON to CSV

JSON Formatter

Paste messy JSON, get it formatted with proper indentation. Also minifies JSON for production use. Validates syntax and highlights errors.

Try it: JSON Formatter

Markdown to HTML Converter

Convert Markdown to clean HTML. Useful for email templates, CMS content, and documentation that needs to render as HTML.

Try it: Markdown to HTML

PDF to Markdown Converter

Extract text from PDF files and convert it to Markdown. Preserves headings, lists, and basic formatting. Good for converting documentation or research papers into editable formats.

Try it: PDF to Markdown

CSV Cleaner

Remove duplicate rows, trim whitespace, delete empty columns. Clean your data before importing it somewhere else.

Try it: CSV Cleaner

Image Converter

Convert images between formats (PNG, JPEG, WebP). Useful for optimizing images for web performance without installing ImageMagick.

Try it: Image Converter

AI Writing and Prompt Tools

Prompt Optimizer

Paste a rough prompt, pick an optimization goal (clarity, detail, coding, creative, or humanize), and get an improved version. Uses AI to restructure your prompt for better model output.

Try it: Prompt Optimizer

Humanize AI Text Tool

Make AI-generated text sound human. Removes common AI tells: em dashes, buzzwords, rule-of-three patterns, overly uniform sentence lengths. Based on our internal copywriting guidelines.

We built this because cheap models like Gemini Flash Lite produce text that reads like a press release. The humanizer strips the AI fingerprint without losing the content.

Try it: Humanize Text

Prompt Library

Browse and copy proven prompt templates for different use cases: coding, analysis, writing, data extraction. Each prompt is tested and optimized for current models.

Try it: Prompt Library

FAQ

Are these tools really free?

Yes. No trial period, no credit card, no signup. The AI-powered features (Prompt Optimizer, Humanize Text, AI Smart Parse) use our API quota, so there may be rate limits during peak usage. Everything else runs entirely in your browser.

Do these tools store my data?

No. The data conversion tools (CSV, JSON, text, image) run 100% in your browser. Nothing is sent to a server. The AI-powered tools send your text to an AI API for processing, but nothing is stored. See our privacy policy for details.

Which tool should I start with?

If you work with AI models: the Benchmark Dashboard. If you work with data: the Text to CSV or CSV to JSON converter. If you write AI prompts: the Prompt Optimizer.

Can I use these tools on mobile?

Yes. Every tool is responsive and works in mobile browsers. The data conversion tools work particularly well on tablets for quick file conversions.

All tools are free and available at dervity.com/tools. Model data sourced from Artificial Analysis Intelligence Index v4.1. Updated July 15, 2026.