Compare Z.ai: GLM 5.1 by Z-ai against Claude Sonnet 4 by Anthropic, context windows of 203K vs 200K, tested across 32 shared challenges. Updated April 2026.
Z.ai: GLM 5.1 and Claude Sonnet 4 are both competitive models. Z.ai: GLM 5.1 costs $1.4/M input tokens vs $3/M for Claude Sonnet 4. Context windows: 203K vs 200K tokens. Compare their real outputs side by side below.
Z.ai: GLM 5.1 is made by z-ai while Claude Sonnet 4 is from anthropic. Z.ai: GLM 5.1 has a 203K token context window compared to Claude Sonnet 4's 200K. On pricing, Z.ai: GLM 5.1 costs $1.4/M input tokens vs $3/M for Claude Sonnet 4.
No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.
Z.ai: GLM 5.1 is 3.4x cheaper per token — worth considering if cost matters.
Claude Sonnet 4 uses 87.9x more emoji
vsAsk them anything yourself
Some models write identically. You are paying for the brand.
178 models fingerprinted across 32 writing dimensions. Free research.
185x
price gap between models that write identically
178
models
12
clone pairs
32
dimensions
279 AI models invented the same fake scientist.
We read every word. 250 models. 2.14 million words. This is what we found.
32 fights queued
Tests an AI's ability to solve a simple but potentially confusing logic puzzle
Sally has 1 sister.
Here is why: All the brothers are in the same family, so they share the same sisters. If each brother has 2 sisters, that means there are exactly 2 girls in the family. Since Sally is one of those girls, the other girl is her only sister.
I need to think through this step-by-step.
Given information:
Let me work out how many sisters are in the family total.
If each of Sally's 3 brothers has 2 sisters, and all the brothers are in the same family, then there must be 2 sisters total in the family.
Since Sally is one of those sisters, and there are 2 sisters total, Sally must have 1 sister.
Therefore, Sally has 1 sister.
Tests an AI's randomness and creativity
Tests an AI's ability to generate vector graphics
Tests an AI's ability to create detailed SVG illustrations of gaming hardware
Tests an AI's humor and creative writing ability
Recreate an interactive, nostalgic Pokémon battle UI in a single HTML file.
Create a 3D building and driving game in a single self-contained HTML file using Three.js. Tests an AI's ability to combine 3D graphics, game logic, and UI interactions on the web.
Recreate an interactive, classic Mario level in a single HTML file.
Tests an AI's ability to replicate an existing UI with Tailwind CSS
Tests an AI's ability to create interactive web elements
Tests an AI's ability to create a detailed world map in SVG format
Generate a single-page, self-contained HTML webapp using Tailwind CSS for a randomly chosen category/industry/niche.
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