100% FREE · RUNS IN YOUR BROWSER
Free online tools for AI builders
Count tokens, estimate LLM costs, format JSON, convert cURL to code, compress images and make QR codes. No sign-up, no upload, no watermark.
- No sign-upOpen a tool and use it. No account, no email, no credits.
- Nothing uploadedText, images and files are processed in your browser and never sent to a server.
- No watermark, no limitsDownload the full result. Use the tools as often as you like.
Popular tools
Token Counter
Count GPT tokens in any text with the real OpenAI tokenizers, and estimate tokens for Claude, Gemini and other models.
Open tool →LLM Cost Calculator
Estimate monthly API cost for every language model on SandBase from your prompt size, reply size and request volume.
Open tool →JSON Formatter & Validator
Format, minify and validate JSON, with the line and column of the first syntax error.
Open tool →cURL to Code Converter
Convert a cURL command into Python requests, JavaScript fetch or Node.js code.
Open tool →Image Compressor
Shrink JPG, PNG and WebP images in your browser, with a quality slider and a before and after size.
Open tool →QR Code Generator
Make QR codes for links, text, Wi-Fi and email, with colors, error correction and PNG or SVG download.
Open tool →All free tools
Search or filter by category. Every tool runs on your device.
Token Counter
Count GPT tokens in any text with the real OpenAI tokenizers, and estimate tokens for Claude, Gemini and other models.
Open tool →LLM Cost Calculator
Estimate monthly API cost for every language model on SandBase from your prompt size, reply size and request volume.
Open tool →JSON Formatter & Validator
Format, minify and validate JSON, with the line and column of the first syntax error.
Open tool →JSON to CSV Converter
Turn a JSON array into a CSV file or spreadsheet, with nested fields flattened into columns.
Open tool →cURL to Code Converter
Convert a cURL command into Python requests, JavaScript fetch or Node.js code.
Open tool →Base64 Encoder & Decoder
Encode text or files to Base64 and decode Base64 back to text, with UTF-8 and URL-safe options.
Open tool →URL Encoder & Decoder
Percent-encode text for URLs and query strings, or decode encoded URLs back to readable text.
Open tool →Image Compressor
Shrink JPG, PNG and WebP images in your browser, with a quality slider and a before and after size.
Open tool →Image Converter
Convert images between JPG, PNG and WebP, one image or a whole batch at a time.
Open tool →Image Resizer
Resize images to exact pixels or a percentage, with presets for social media and AI model inputs.
Open tool →QR Code Generator
Make QR codes for links, text, Wi-Fi and email, with colors, error correction and PNG or SVG download.
Open tool →Free tools on live data
These run in SandBase Lab on live platform data. Sign in with your SandBase account to use them.
TikTok Fake Views Checker
Paste a TikTok video link to see a fake view score, engagement ratios and follower growth.
LAB · FREETikTok Engagement Rate Calculator
Enter a TikTok username to get the engagement rate, average views and posting frequency.
LAB · FREEInstagram Engagement Rate Checker
Engagement rate of recent posts, a benchmark against similar accounts and a fake follower check.
LAB · FREEYouTube Transcript Generator
Full transcript with timestamps, an AI summary and chapters. Download TXT or SRT.
LAB · FREEChina Trending Today
Live Weibo, Douyin, Kuaishou and Zhihu hot lists, with an AI summary of what is trending.
LAB · FREELLM API Price Comparison
Input, output and cache prices for every language model on SandBase, side by side.
Frequently asked questions
- Are these tools really free?
- Yes. They run in your browser, so they cost us nothing to serve per use. There is no trial, no credit counter and no watermark.
- Do my files leave my device?
- No. Text, images and files are read and processed by JavaScript in your browser. Nothing is uploaded, which also means the tools keep working on large files.
- Why does SandBase make free tools?
- They are the small jobs that come up while building with AI models and APIs: counting tokens, checking costs, cleaning JSON, converting images. When you need the models themselves, they are one API key away on SandBase.
- Can I suggest a tool?
- Yes. Email [email protected] with the tool you need and what you would use it for.
More resources
Use cases
Ready-made scenarios for social, SEO, content and research work, with every Model and API each one uses.
GUIDEAgent ecosystem
Runtimes, sandboxes, memory, tool protocols, gateways and observability projects for production Agents.
TOOLSandBase CLI
Connect Codex, Claude Code, Cursor and 20+ other AI clients to SandBase with one command.
PROGRAMHackathon support
API credits, sandboxed runtime, starter workflows and builder help for AI Agent hackathon teams.
CODEOpen source
SDKs, the CLI and working examples you can read, fork and run.
COMPARECompare models
Side-by-side prices, context windows and benchmarks for popular language models.