Free · No sign-up needed
Sahi Padhai is a free place to learn AI, electronics and computer networks by doing. Change a setting in a live simulator, work through hands-on courses, solve a daily puzzle, and keep up with plain-language tech news in English and Hindi.
Old 'day in the life' reels are back, with jokes that office food earned 60,000 people an exit offer. Here is what Microsoft actually said, and what it didn't.
Tokenize with BPE, watch attention heads, rotate positions with RoPE, size a KV cache, route tokens to experts and quantize weights.
Chunk a handbook, search it by meaning, fuse BM25 with dense retrieval, rerank, measure recall and NDCG, and keep the index fresh.
Drag vectors to see a span collapse, warp the grid with a matrix, hunt eigenvectors by hand, run Gram–Schmidt step by step, and watch a circle become an ellipse under the SVD.
Find principal components, run k-means and EM step by step, tame overfitting with ridge and lasso, and compare kNN, trees, naive Bayes, SVMs and boosting.
Build neural networks from scratch. Explore 3D error surfaces, optimizers, backpropagation, overfitting and convolutions.
Sampling, filtering, Fourier transforms, segmentation, SIFT and HOG, applied to a live image you can change.
Simulate circuits, diodes, transistors and op-amps. Plot V-I curves, load lines and Bode plots, with a live oscilloscope.
Design topologies, configure routers and watch packets travel hop by hop through routing, DHCP and the OSI layers.
Run a business end to end: orders, warehouse, transport and finance. Sign in to save your progress.
Every row, column and box gets the digits 1 to 6. Small grid, real logic.
Play today’s puzzle →Draw a single path that fills the grid and passes the numbers in order. Five grids a day, 4×4 up to 6×6.
Play today’s puzzle →Put the letters of five AI terms back in order, with a clue for each. Pick a topic and Easy or Hard.
Play today’s puzzle →Guess an AI term one letter at a time from its clue, before six wrong letters fill the bar.
Play today’s puzzle →A small daily crossword whose answers are all AI and machine learning terms.
Play today’s puzzle →Match six AI terms to their meanings with as few mistakes as you can.
Play today’s puzzle →Short, clear lessons that explain the concept without the fog.
Change parameters in a live simulator and see the result instantly.
Interview-style questions with hints and worked answers.
Take Retrieval-Augmented Generation from a demo to a production system: chunking and embeddings, vector indexes at scale, hybrid search, reranking and query transformation, rigorous evaluation, keeping knowledge fresh, agentic and graph-based RAG, memory, and multimodal documents.
A map of what AI engineer and GenAI interviews actually test, and the study path through it: machine learning foundations, transformer internals, efficiency, alignment and fine-tuning, prompting and retrieval, evaluation, and the failure modes every interviewer asks about.
Learn the complete deep learning with this course starting from basics to current day attention networks.
What are the different types of NVIDIA GPU, from the GeForce RTX gaming cards to the L4, L40S and H100 you rent in the cloud, with India prices. Plus the AMD Radeon alternative, how Apple competes, how much memory an LLM actually needs, and why running a model is not the same as training one.
Sol, Luna, Terra and Astra are OpenAI's model codenames, and what they rank changed between GPT-5.6 and GPT-6.1. Which is the flagship, which is cheap, and why OpenAI's Astra is not Google's Project Astra.
From 9 October 2026 free Gemini users get Flash-Lite only, and AI Plus loses Pro. The full plan-by-plan table of which Gemini model each tier can reach, and what the new effort settings cost you.
