Free online developer tools

20 tools

Small utilities developers reach for daily: JSON and YAML formatters, Base64 and URL encoders, regex testers, JWT decoders, diff viewers and cron helpers. Prefer tools marked as running in your browser when you paste tokens, keys or production data, because nothing is uploaded.

Showing 1–20 of 20

0.823score
Llama Coder
Nutlope
Describe an app idea and an open model generates a runnable code project with a preview.
ArtifactAINo sign-up★ 7.1Kdeveloper tools
0.816score
make real
tldraw
Draw a user interface on a canvas and a vision model turns it into working HTML; uses your own API key.
ArtifactAINo sign-up★ 5.4Kdeveloper tools
0.803score
database.build
Supabase community
Postgres running in the browser through PGlite, paired with an AI assistant for schemas, CSV imports and diagrams.
ArtifactAINo sign-upIn-browser★ 2.9Kdeveloper tools
0.784score
Napkins.dev
Nutlope
Upload a wireframe or design screenshot and get a React and Tailwind app generated from it.
ArtifactAINo sign-up★ 1.5Kdeveloper tools
0.730score
WebNN Samples
W3C Web Machine Learning community
Sample apps and an expression playground for the WebNN API, which runs neural networks on device hardware from the browser.
ArtifactAINo sign-upIn-browser★ 188developer tools
0.661score
InstantCoder
osanseviero
Generates a small web app from a prompt and shows the result immediately.
ArtifactAINo sign-up★ 1.5Kdeveloper tools
0.647score
Screenshot to HTML
HuggingFaceM4
Upload a screenshot of a web page and get HTML that approximates it.
ArtifactAINo sign-up★ 934developer tools
0.624score
Qwen3 Coder WebDev
Qwen
Describe a web page or small app and Qwen3-Coder writes the HTML, with a live preview.
ArtifactAINo sign-up★ 1.2Kdeveloper tools
0.621score
Qwen2.5 Coder Artifacts
sambanovasystems
Describe a small app and get generated code that previews in the page.
ArtifactAINo sign-up★ 276developer tools
0.619score
Code Llama Playground
codellama
Generate and complete code by typing a prompt into the Code Llama playground.
ArtifactAINo sign-up★ 251developer tools
0.588score
DeTikZify
nllg
Converts a sketch or figure image into TikZ code for LaTeX documents.
ArtifactAINo sign-up★ 91developer tools
0.583score
GitHub Issue Generator
reach-vb
Writes a GitHub issue draft with SmolLM2 running locally in the browser on WebGPU.
ArtifactAINo sign-upIn-browser★ 56developer tools
0.580score
WebLLM Structured Generation
mlc-ai
Generate structured output such as JSON from an in-browser WebLLM model.
ArtifactAINo sign-upIn-browser★ 50developer tools
0.576score
Beeceptor
Beeceptor
Spins up a mock REST, SOAP or GraphQL endpoint with rules and generated responses, and logs incoming requests.
ArtifactAINo sign-updeveloper tools
0.573score
CodeConvert AI
CodeConvert AI
Translates source code between more than 60 programming languages; the page says free tools work without signup.
ArtifactAINo sign-updeveloper tools
0.561score
PGlite Semantic Search
thorwebdev
Vector search over documents using a Postgres running in WebAssembly (PGlite) inside the browser.
ArtifactAINo sign-upIn-browser★ 20developer tools
0.478score
Chrome Built-in Model Playground
Simon Willison
Runs prompts against the language model built into Chrome, downloading it on first use.
ArtifactAINo sign-upIn-browserdeveloper tools
0.477score
Claude Token Counter
Simon Willison
Counts tokens for text and image attachments across several Claude models using Anthropic token-counting API and your key.
ArtifactAINo sign-updeveloper tools
0.477score
llm-lib Demo
Simon Willison
Try one JavaScript library against OpenAI, Anthropic or Gemini models by picking a provider and pasting a key.
ArtifactAINo sign-updeveloper tools
0.477score
OpenAI Prompt Caching Playground
Simon Willison
Sends prompts with different structures to OpenAI and shows how many tokens were served from cache.
ArtifactAINo sign-updeveloper tools