GLM-5.3 vs Seed 2.1 Turbo: Specs & Benchmark Comparison

GLM-5.3 is developed by Zhipu AI, while Seed 2.1 Turbo comes from ByteDance. Seed 2.1 Turbo was released in June 2026, and GLM-5.3 followed 2 months later in August 2026. GLM-5.3 has a published size of about 753 billion parameters; ByteDance has not disclosed the parameter count of Seed 2.1 Turbo.

The two models share 7 published benchmarks. GLM-5.3 leads on 6 of them, Seed 2.1 Turbo on 1. The widest gaps are on Program Bench, where Seed 2.1 Turbo scores 49.4% against 19.0%; Toolathlon, where GLM-5.3 scores 73.0% against 49.1%. Averaged across everything we track, GLM-5.3 sits at 52.2% and Seed 2.1 Turbo at 61.0%.

GLM-5.3 is available through an API at $1.40 per million input tokens with a 1M-token context window. We do not track a hosted API for Seed 2.1 Turbo, so pricing and context cannot be compared directly.

CharacteristicGLM-5.3Seed 2.1 Turbo
CompanyZhipu AIByteDance
Release DateAugust 14, 2026June 24, 2026
Parameters753B
MultimodalNoYes
Context (input)1.0M
Context (output)131K
Input Price / 1M$1.40
Output Price / 1M$4.40
Average Score52.2%61.0%
Benchmarks
Program Bench19.0%49.4%
Toolathlon73.0%49.1%
PostTrainBench39.8%18.3%
Terminal-Bench 2.188.0%67.6%
CyberGym84.5%67.0%
NL2Repo58.0%43.7%
Humanity's Last Exam62.5%54.6%

Visual Benchmark Comparison

GLM-5.3
Seed 2.1 Turbo
Program Bench0.2 vs 0.5
0.2
0.5
Toolathlon0.7 vs 0.5
0.7
0.5
PostTrainBench0.4 vs 0.2
0.4
0.2
Terminal-Bench 2.10.9 vs 0.7
0.9
0.7
CyberGym0.8 vs 0.7
0.8
0.7
NL2Repo0.6 vs 0.4
0.6
0.4
Humanity's Last Exam0.6 vs 0.5
0.6
0.5

Verdict

GLM-5.3 leads in 1 out of 2 comparison categories.

Overall Performance

Both models show comparable average scores: GLM-5.3 — 0.5, Seed 2.1 Turbo — 0.6.

Recency

GLM-5.3 is newer: released 8/14/2026 vs 6/24/2026.

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Frequently Asked Questions

Which is better for coding — GLM-5.3 or Seed 2.1 Turbo?
Direct comparison on the SWE-Bench benchmark is not available. We recommend reviewing other metrics on the comparison page.
Which model is cheaper — GLM-5.3 or Seed 2.1 Turbo?
API pricing data is available on the individual model pages.
Which has a larger context window — GLM-5.3 or Seed 2.1 Turbo?
Context window data is available on the individual model pages.

The GLM-5.3 and Seed 2.1 Turbo comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the GLM-5.3 or Seed 2.1 Turbo page. See also the complete list of AI model comparisons.