As of August 28, 2026, GLM-5.3-Flash is 62% cheaper per million tokens than Grok Code Fast 1. GLM-5.3-Flash is $0.15 / $0.50 per million input/output tokens versus Grok Code Fast 1 at $0.20 / $1.50. Sources: https://docs.z.ai/guides/overview/pricing and https://docs.x.ai/docs/models
Sources: Z AI pricing (https://docs.z.ai/guides/overview/pricing); xAI API pricing (https://docs.x.ai/docs/models)
GLM-5.3-Flash
Z AI
Input
$0.15
Output
$0.50
Grok Code Fast 1
xAI
Input
$0.20
Output
$1.50
Token pricing, specs, and benchmarks side by side
Each bar is share of the current leader on that eval. Click a row to open the board.
Terminal-Bench. Left is cheaper. Up is a higher score. The line is the best score you can buy at each price.
GLM-5.3-FlashGrok Code Fast 1Verdict
GLM-5.3-Flash offers both lower pricing and stronger benchmark performance across the board, making it the clear value leader in this comparison.
As of August 28, 2026, GLM-5.3-Flash is 62% cheaper on blended LLM API pricing. GLM-5.3-Flash costs $0.15 per million input tokens and $0.50 per million output tokens ($0.65 blended 1M-in + 1M-out). Grok Code Fast 1 costs $0.20 / $1.50 per million tokens ($1.70 blended). Sources: https://docs.z.ai/guides/overview/pricing and https://docs.x.ai/docs/models. The cheapest LLM for your app still depends on how many output tokens you generate.
GLM-5.3-Flash Z AI API pricing is $0.15 input and $0.50 output per million tokens via Z AI. Grok Code Fast 1 xAI API pricing is $0.20 input and $1.50 output per million tokens via xAI. Use those four numbers, not ChatGPT Plus or Claude Pro subscription prices, when you are comparing APIs.
Grok Code Fast 1 has a published SWE-bench Verified score of 70.8%. GLM-5.3-Flash does not have that eval on this page yet.
GLM-5.3-Flash supports a 1M token context window, while Grok Code Fast 1 supports 256K tokens. GLM-5.3-Flash offers a larger context window. Filling a larger window bills more input tokens, so the cheaper-per-million model can still cost more on long documents.
GLM-5.3-Flash leads on 1 of 1 shared benchmarks versus Grok Code Fast 1's 0 wins. Check the comparison table for GPQA Diamond, SWE-bench, MMLU, HLE, and the other evals we track. Token price and benchmark score together are the usual LLM comparison, not either number alone.
Both GLM-5.3-Flash and Grok Code Fast 1 are production API models. For cost-sensitive production traffic, GLM-5.3-Flash has better economics on the blended 1M-in + 1M-out scale. For maximum capability, weight the benchmark table for your domain. Many production stacks route cheap models for drafts and a frontier model for the hard turn, which is usually cheaper than sending everything to the expensive API.
Yes. Call GLM-5.3-Flash through Z AI and Grok Code Fast 1 through xAI with separate API keys, or through a gateway that already wraps both. Keep prompts in tokens, not characters, when you estimate the invoice. AnotherWrapper templates can swap providers without rewriting auth and billing.
List rates are the latest published Z AI API pricing and xAI API pricing, quoted per million tokens. Official rate sheets: https://docs.z.ai/guides/overview/pricing and https://docs.x.ai/docs/models. Prompt caching, batch APIs, and committed-use discounts can change the invoice. Benchmark scores are from official publications and independent evals, updated as new numbers land.
GLM-5.3-Flash supports up to 131K output tokens per request, while Grok Code Fast 1 supports up to 10K output tokens. Output tokens are usually the expensive half of API pricing, so a higher max output cap is a capability, not a discount.
Grok Code Fast 1 has a measured throughput of approximately 76.4 tokens/second. Throughput data for GLM-5.3-Flash is not yet available. Throughput (tokens per second) and time-to-first-token are why two models with the same per-million-token price can still feel different in chat and agents.
Use the model pickers at the top of this LLM comparison. Search any model in the index and the URL updates. Open GLM-5.3-Flash or Grok Code Fast 1 from the sidebar for the single-model API pricing page, or go back to the LLM pricing table to sort by cheapest blended cost.
This comparison covers API pricing, context window, throughput, and benchmark scores. GLM-5.3-Flash costs $0.15/M input and $0.50/M output. Grok Code Fast 1 costs $0.20/M input and $1.50/M output.
Rank both on the LLM leaderboard, SWE-bench, and Humanity's Last Exam.
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