ModelsCompareBest forBenchmarksStatusPricingAPI
Compare / head-to-head

GLM-5.1vsStep 3.5 Flash

GLM-5.1 and Step 3.5 Flash split their 2 shared benchmarks evenly. Step 3.5 Flash has the larger context window (256K tokens).

Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.

Shared benchmarks
1 – 1
even split
Cheaper per token
list price, input + output
Larger context
Step 3.5 Flash
256K tokens
Provider uptime (30d)
— · —
Z.ai · StepFun
GLM-5.1
Z.ai · released 2026-04-07
text
Context
200K
Max out
131K
Input /1M
$1.4
Output /1M
$4.4
Cached /1M
$0.26
Scores
7 · 7 core
Step 3.5 Flash
StepFun · released 2026-02-12
text
Context
256K
Max out
Input /1M
Output /1M
Cached /1M
Scores
18 · 5 core
Quality

Benchmark matrix

BenchmarkGLM-5.1Step 3.5 FlashΔEdge
Reported by both · 2
AIME 202695.8% matharena96.7% matharena-0.9 ptStep 3.5 Flash
LMArena Elo1462.4 1403.7 +58.7GLM-5.1
Only GLM-5.1 reports · 5
GPQA Diamond89.9% epochnot reported
FrontierMath Tiers 1-3 v2 (Epoch AI run)36.8% epochnot reported
OTIS Mock AIME 2024-2025 (Epoch AI run)93.3% epochnot reported
SimpleQA Verified34% epochnot reported
SWE-bench Verified (Epoch AI run)74.2% epochnot reported
Only Step 3.5 Flash reports · 15
SWE-bench Verifiednot reported74.4%
AIME 2025not reported97.3%
BrowseCompnot reported51.6%
BrowseComp (with context manager)not reported69%
BrowseComp-ZHnot reported66.9%
BrowseComp-ZH (with context manager)not reported73.7%
GAIA (no file)not reported84.5%
HMMT 2025 (Feb/Nov average)not reported96.2%
IMOAnswerBenchnot reported85.4%
LiveCodeBench v6not reported86.4%
ResearchRubricsnot reported65.3%
Tau2-Benchnot reported88.2%
Terminal-Bench 2.0not reported51%
xbench-DeepSearch 2025.05not reported83.7%
xbench-DeepSearch 2025.10not reported56.3%
Scores tagged "epoch" or "matharena" are independent runs, used only where the lab has not published its own; ⚠ marks rows MathArena flags as released after the competition. Higher is better on every row. Δ is GLM-5.1 minus Step 3.5 Flash in the benchmark's own unit. "Not reported" means the lab has not published that figure; it is not a zero. ↗ opens the source.
Specs & pricing

Side by side

SpecGLM-5.1Step 3.5 FlashEdge
Context window200K tokens256K tokensStep 3.5 Flash
Max output131K tokens
Input price / 1M$1.4
Output price / 1M$4.4
Cached input / 1M$0.26
Input + output / 1M
Lower is cheaper. List prices; batch, tool and regional fees excluded.
$5.8
ModalitiestexttextTie
Released2026-04-072026-02-12
Cited benchmark scores718
Reliability

Provider status

All providers
More matchups

GLM-5.1 vs …

More matchups

Step 3.5 Flash vs …

Built by Respan
Which one wins on your data?

Public benchmarks are a starting point. Run GLM-5.1 and Step 3.5 Flash on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.