Why high: an exact fingerprint shared with 8 models.
Z.ai: GLM 5.3 Flash is Z.ai's model, and its measured tokenizer sits in Z.ai's own signature group alongside its sibling models. Measured models from Aion Labs carry the same vocabulary, which reads as reuse of Z.ai's tokenizer line and questions nobody's authorship; they are listed under "Shares this fingerprint" below.
| We checked | What we found | Where it came from |
|---|---|---|
| How it counts tokens | Counts every one of the 50 test strings exactly like 8 other models | tk_133b086c |
| How its API is set up | A combination of settings no other listing in the catalogue uses | api_8d90b7bc |
| How much it can read and write | Reads up to 1,048,576 tokens at once, writes up to 943,717 | its own listing |
| Whether it thinks before answering | Always reasons, and cannot be turned off, at max, high, low, max by default | its own listing |
| Who served our requests | Relace | we measured it, 5 October 2026 |
| Measured twice | The 5 October 2026 reading agreed with the 3 September 2026 reading on every one of the 50 strings clean in both: the tokenizer behind this name held. | 50/50 agree |
Click a row to open the full comparison.
We sent Z.ai: GLM 5.3 Flash fifty short pieces of text and recorded what each one cost it in tokens. The bars below are those costs. Two models built on the same tokenizer produce the same bars; a model built on a different one produces a different set, which is what makes this a fingerprint.
Overhead subtracted: 12 prompt tokens.
GLM-5.3-Flash is a native multimodal model from Z.ai. It is suited for efficient coding and long-horizon agent tasks. Its hybrid sparse and linear attention architecture maintains accurate long-context behavior while...
Supported parameters
frequency_penaltyinclude_reasoninglogit_biaslogprobsmax_tokensmin_pparallel_tool_callspresence_penaltyreasoningreasoning_effortrepetition_penaltyresponse_formatseedstopstructured_outputstemperaturetool_choicetoolstop_ktop_logprobstop_p
defaults: {"temperature":1,"top_p":0.95}
