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Claude Opus 5 vs GLM-5.3

Claude Opus 5Anthropic
GLM-5.3Z.ai
Our take

Claude Opus 5 wins 4 of 4 categories, but GLM-5.3 is 4.7× cheaper for everyday text work. Pick Claude Opus 5 when quality matters most, GLM-5.3 at volume.

Overall86Best61
Coding84Best68
Writing86Best70
Support84Best67
Value71Best54
Input / 1M$5.00$1.40Best
Output / 1M$25.00$4.40Best
Blended / 1M$10.00$2.15Best
Context window1M1M
Open weightsNoYes
Released24 Jul 202614 Aug 2026

Your monthly bill

50k
Claude Opus 5$2.0k
GLM-5.3$430Cheapest
List prices, a quarter of the tokens as output. Scores are provisional, from Arena and Epoch AI.