Claude Sonnet Price vs GLM-5.3: GLM Wins on Cost

Posted on Nov 4 • Originally published at aitecharchive.com

Verdict: GLM-5.3 is the cheaper model for most coding work, and it wins on list rates. The claude sonnet price is $2 per million input tokens and $10 per million output tokens, while GLM-5.3 is $1.40 input and $4.40 output. Sonnet narrows the gap only when your workload leans heavily on prompt caching, and it keeps a clear budgeting advantage because Anthropic has made its rate permanent.

Claude Sonnet 5 launched on 30 June 2026 with introductory pricing, and Anthropic's changelog later confirmed that $2 input and $10 output per million tokens is now permanent. Sonnet 5.5, released on 28 September, keeps the same $2 / $10 rates and halves cache reads to $0.10 per million tokens. Anthropic also says it needs fewer tokens for the same task, by up to 30% per task according to its own figures.

Other levers matter for real bills. Per the BenchLM tracker of Anthropic's list prices, Sonnet 5 charges $2.50 per million for five-minute cache writes, $4 for one-hour writes and $0.20 for cache reads, and the Batch API halves the rates to $1 input and $5 output. For a deeper look at charges that sit outside the headline rate, see our piece on Claude Sonnet 5 pricing and hidden costs.

GLM-5.3 is Zhipu's open-weights flagship, and Z.ai lists it at $1.40 per million input tokens, $0.26 cached input and $4.40 per million output. Third-party trackers such as LLM Reference and SayGM show that GLM 5.1, 5.2 and 5.3 have shared one list rate since April 2026. The weights are MIT-licensed, so independent hosts can serve the model at or below that rate.

Z.ai also sells a subscription route. Its GLM Coding Plan starts at $18 per month with 2,000 credits per five hours. Quality is a separate question, and our Sonnet 5 vs GLM-5.2 coding comparison covers how the two behave on real tasks.

Take one scenario: a coding agent consuming 80M input and 20M output tokens a month. The arithmetic below uses each vendor's list rate, and the Rs column uses USD 1 = Rs 94.93, the 3 November rate.

On these inputs GLM-5.3 is about 44% cheaper than Sonnet 5 list, a saving of $160 a month (derived from the Anthropic and Z.ai rates). DeepSeek's V4-Pro and V4.1-Flash prices apply off-peak, and peak hours (01:00 to 04:00 and 06:00 to 10:00 UTC on weekdays) cost double. For a wider provider view, see Gemini vs Claude API pricing and DeepSeek V4-Pro's cost against frontier models.

Partly. Agents re-read the same files and instructions repeatedly, and Sonnet's cache reads cost $0.20 per million tokens. If 70% of the 80M input tokens are cache reads and the remaining 30% are billed at the base $2 (a simplification that ignores cache-write premiums), effective input falls to $0.74 per million. That puts the month at about $259 on Sonnet 5, using Anthropic's rates and BenchLM's cache figures. On Sonnet 5.5, where cache reads are $0.10, the same pattern lands near $254.

GLM-5.3 remains cheaper at $200 per Z.ai's list, and that figure applies no cache discount at all, so the real gap is smaller than the uncached comparison suggests but not closed. Caching is the one area where Anthropic's economics are clearly better than Z.ai's $0.26 cached input.

Three places. First, rate certainty: Anthropic has declared the $2 / $10 rate permanent, which makes forecasting simple. Second, effort levels: Anthropic positions Sonnet 5 as close to Opus 4.8 on agentic work at a lower price, and lets you trade cost for capability per request. Third, hard multi-step tasks, where one failed run costs more in engineer time than the token saving. For a three-way benchmark, see Gemini 3.7 Flash vs Sonnet 5 vs GPT-5.6.

There is also a market point. Kimi K3.1 Pro is priced at the same $2 / $10, as reported by Fello AI, so a closed-model premium at the API layer no longer exists across the board.

Q: What is the current Claude Sonnet price per million tokens? A: Sonnet 5 and Sonnet 5.5 both list at $2 input and $10 output per million tokens, and Anthropic has said the Sonnet 5 rate is permanent.

Q: Is GLM-5.3 cheaper than Claude Sonnet? A: Yes on list rates. GLM-5.3 costs $1.40 input and $4.40 output per million tokens, against Sonnet's $2 and $10.

Q: Does prompt caching make Claude cheaper than GLM-5.3? A: Not in the scenario above. Even with 70% cache reads, Sonnet came to about $259 per month against GLM-5.3's $200, based on Anthropic, BenchLM and Z.ai rates.

Q: How much is the monthly saving in rupees? A: At Rs 94.93 per dollar, the example workload costs Rs 18,986 on GLM-5.3 against Rs 34,174 on Sonnet 5 list, using the Z.ai and Anthropic rates.

Q: Can I use GLM-5.3 with Claude Code? A: Z.ai offers an OpenAI-compatible endpoint, and its Coding Plan targets coding tools. DeepSeek offers an Anthropic-compatible endpoint, which is the simpler route for Claude Code, so test your own workflow before committing.