GLM-5.3-Flash vs Step 5 Preview: which is cheaper?

GLM-5.3-Flash and Step 5 Preview are close rivals from Z AI and StepFun. Price separates them more than anything else; on a blended basis Step 5 Preview costs 6 times as much as GLM-5.3-Flash. Everything below is read from the benchmark, price and speed data in Franklin AI's catalogue; nothing here comes from a hands-on test.

Token pricing and a sample bill

GLM-5.3-Flash lists $0.15 per million input tokens and $0.50 per million output tokens; Step 5 Preview lists $1.00 and $2.70. For output tokens, Step 5 Preview is 5.4 times the price of GLM-5.3-Flash.

Take 1 million input tokens and 200,000 output tokens: that comes to $0.25 on GLM-5.3-Flash and $1.54 on Step 5 Preview. A bigger example, a chat app with 50,000 sessions of 800 input and 300 output tokens, costs $13.50 on GLM-5.3-Flash and $80.50 on Step 5 Preview: a gap of $67.00. Blended at three input tokens per output token, the effective rates are $0.238 for GLM-5.3-Flash and $1.425 for Step 5 Preview.

Waiting time

Once a response is under way, GLM-5.3-Flash produces roughly 56 tokens per second against 151 tokens per second for Step 5 Preview. That makes Step 5 Preview roughly 2.7 times as fast at writing. The wait for the first token averages 1.6 seconds on GLM-5.3-Flash against 0.91 seconds on Step 5 Preview. GLM-5.3-Flash waits 1.8 times as long before its first token.

For a 400-token response, first token plus generation comes to roughly 8.8 seconds on GLM-5.3-Flash and 3.6 seconds on Step 5 Preview.

Release timing

Step 5 Preview arrived on September 18, 2026, 23 days after GLM-5.3-Flash (August 26, 2026). They are effectively contemporaries.

Benchmark scores

The catalogue puts GLM-5.3-Flash at 27.8 and Step 5 Preview at 28.5 on its intelligence index. On an aggregate like this, under a point is effectively level.

For context, that places GLM-5.3-Flash 63rd and Step 5 Preview 61st out of 109 scored models still on offer.

Specialist coding and math indexes are missing for both, so treat the overall score as the only capability signal here.

Value for money

Per point of intelligence index, GLM-5.3-Flash costs $0.0085 of blended price per million tokens and Step 5 Preview $0.050. Step 5 Preview costs 5.9 times as much per point, which is the price of its lead.