Free Developer Tools Directory
Fast, private, browser-based tools with zero sign-ups and zero data uploads. Token counters, JSON to code generators, formatters, and career trackers.
Developer Roadmap Generator
Pick a goal, your level and your weekly hours, and get a dated week-by-week plan built from free learning paths, with real video links and milestones.
DSA Sheet Tracker
Track Blind 75 and NeetCode 150 problem by problem, flag what needs revision, and see progress per topic. Saved in your browser, no account.
GitHub Profile Scorer
Score your GitHub profile with a transparent rubric (README, stars, documentation, commit recency) and generate an embeddable SVG badge.
Kokoro 82M TTS Playground
Test open-source Kokoro-82M neural voices directly in your browser. Fast CPU synthesis, zero queue delays, and direct WAV audio downloads.
Markdown to Speech Reader
Turn README files, architecture RFCs, and technical docs into clear spoken audio. Automatically strips noisy code fences and formatting.
YouTube Voiceover Generator
Generate studio-grade narration for tech tutorials, coding Reels, and system design explainers. Paced sentence by sentence for video editing.
Text to Speech & WAV Generator
Convert text into natural human speech using open-weight AI models. Zero sign-up required, preview audio instantly, and export clean WAV files.
LLM Token Counter
Estimate token counts across GPT-4o, Claude 3.5, Llama 3, and Gemini before dispatching prompts to model APIs. With embeddable widget.
Claude Token Counter
Calculate prompt tokens for Anthropic Claude 3.5 Sonnet, Claude 3.7, and Opus. Manage your 200k context window accurately.
GPT Token Counter
Estimate prompt token consumption for OpenAI GPT-4o, ChatGPT, and reasoning models. Avoid rate limits and control inference costs.
Gemini Token Counter
Estimate prompt tokens for Google Gemini 1.5 Flash, 1.5 Pro, and Gemini 2.0. Budget million-token context payloads effectively.
Llama Token Counter
Calculate prompt tokens for Meta Llama 3, 3.1, 3.3, and open source LLMs. 100% private in-browser calculation.
LLM API Cost Calculator
Estimate model API spend per call, per 1K, per 1M and per month across GPT, Claude, Gemini, Llama and DeepSeek with the math shown.
Chat Messages Array Builder
Compose an LLM conversation turn by turn and export it as OpenAI JSON, Anthropic messages, a Python SDK call, or curl.
Free AI Code Generator
Transform plain English problem descriptions into clean, production-ready code snippets across modern programming languages.
AI Project Generator
Convert rough software concepts into structured project briefs, database schemas, and step-by-step implementation milestones.
JSON to TypeScript
Turn a JSON sample into TypeScript interfaces with nested types, arrays and nullable fields. Drop-in ready.
JSON to Zod Schema
Convert raw JSON payloads into runtime-validating Zod schemas with automatic TypeScript type inference.
JSON to Python Pydantic
Generate modern Python Pydantic v2 BaseModel classes with Field aliases and Optional type annotations from JSON.
JSON to Go Struct
Generate idiomatic Golang structs with json tags and pointer fields for nullables directly from JSON responses.
JSON to Rust Struct (Serde)
Generate typed Rust structs equipped with serde Serialize and Deserialize traits and Option wrappers.
JSON to SQL DDL Schema
Generate PostgreSQL and MySQL CREATE TABLE DDL statements from JSON object keys with automatic column typing.
JSON to Kotlin Data Class
Convert JSON into clean Kotlin data classes with kotlinx.serialization and Jackson SerialName annotations.
JSON to Java Record
Generate modern Java 17+ record classes with Jackson JsonProperty annotations from JSON samples.
JSON Formatter & Validator
Beautify, minify, and validate JSON payloads with native parser error diagnostics. Your data never leaves your browser.
YAML to JSON Converter
Convert YAML to JSON and JSON to YAML in both directions with a one-click swap, two-space output and inline parse errors.
JSONL Validator & Viewer
Validate newline-delimited JSON line by line, preview valid rows as a table, and detect common fine-tuning dataset schemas.
Open Graph & Meta Tag Previewer
Preview a link as it would appear on Google, Facebook, LinkedIn, X and Slack, then copy a ready-to-paste meta tag block.
Secret & API Key Scanner
Scan pasted code, config or logs for exposed provider keys, tokens, private keys and hardcoded credentials. No telemetry.
PX to REM Converter
Convert px to rem and back against a configurable base font size, with a reference table and copy buttons for common values.
Cron Expression Generator
Build a five-field crontab schedule from presets, read it in plain English, and preview the next five run times in your local timezone.
Case Converter
Convert text to camelCase, snake_case, kebab-case, Title Case, a URL slug and more at once, with per-row copy.
Unix Timestamp Converter
Convert epoch values to human dates and back with unit auto-detection, timezone selection, ISO 8601, RFC 2822 and relative time.
Word & Character Counter
Count words, characters, sentences, paragraphs, and reading time live as you type, with social media length indicators.
Why our utilities run 100% in your browser
Zero Server Uploads
Most online formatters post your text to a server. Here, your JSON, prompt tokens, and confidential drafts never leave your local RAM.
Safe for API Keys & NDAs
Paste server configs, proprietary schemas, and API tokens with confidence. Nothing is logged, cached, or transmitted across a wire.
Offline Ready
Once the page is loaded, you can disconnect your internet and every single client-side utility continues functioning instantly.