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GLM 5.3 vs Seed 2.0 Pro

Close to a tie overall. Seed 2.0 Pro costs 33% less for the same work.

GLM 5.3

by Z.ai · #10 of 67 overall

Coming soon · price at launch
Context
1M
Input / 1M
$0.90
Output / 1M
$4.00

Seed 2.0 Pro

by ByteDance · #9 of 67 overall

Coming soon · price at launch
Context
250K
Input / 1M
$0.50
Output / 1M
$3.00

Better overall

About even

Grade 83.8 vs 84.3

Cheaper

Seed 2.0 Pro

33% less, $1.13 vs $1.68 blended

Larger context

GLM 5.3

1M vs 250K tokens

Head to head

Public benchmarks. Longer is better; each value links to its source.

LMArena TextElo-style rating · LMArena (CC BY 4.0) · Oct 15, 2026
LMArena WebDevElo-style rating · LMArena (CC BY 4.0) · Oct 13, 2026
Seed 2.0 ProSeed 2.0 Pro: —
LMArena CodingElo-style rating · LMArena (CC BY 4.0) · Oct 15, 2026
SWE-bench Verified% of issues resolved · SWE-bench · Feb 14, 2026 · reference
GLM 5.3GLM 5.3: —
SWE-Bench Pro% of tasks resolved · Scale AI SWE-Bench Pro · Feb 15, 2026 · reference
GLM 5.3GLM 5.3: —
Terminal-Bench 3.0% of tasks passed · Terminal-Bench · Aug 25, 2026 · reference
Seed 2.0 ProSeed 2.0 Pro: —
Terminal-Bench 2.1% of tasks passed · Terminal-Bench · Aug 25, 2026 · reference
Seed 2.0 ProSeed 2.0 Pro: —
Terminal-Bench 2.0% of tasks passed · Terminal-Bench · Feb 15, 2026 · reference
GLM 5.3GLM 5.3: —

GLM 5.3Seed 2.0 Prov = reported by the model’s maker. — = no public score yet. Arena bars span the range across every model we grade.

What it costs you

Drag to match your monthly usage.

GLM 5.3$340 /month
Seed 2.0 Pro$220 /month

Seed 2.0 Pro saves you $120 a month at this usage, $1,440 a year.

At a glance

AttributeGLM 5.3Seed 2.0 Pro
Made byZ.aiByteDance
AvailabilityComing soonComing soon
Overall gradeExcellent · 83.8Excellent · 84.3
Overall rank#10 of 67#9 of 67
Input price$0.90 per 1M$0.50 per 1M
Output price$4.00 per 1M$3.00 per 1M
Context window1,048,576 tokens256,000 tokens
Reasoning levelsNoNo
Reads imagesNoYes
Model IDglm-5.3seed-2.0-pro

Try both with one key

Same endpoint, same key, both hosted in the USA. Change one word to switch models, in Claude Code, Cursor, Cline or your own code.

Get your API key
# Ask either model the same thing
curl https://fullsendai.com/v1/chat/completions \
  -H "Authorization: Bearer $FULLSEND_API_KEY" \
  -d '{"model": "glm-5.3", "messages": [...]}'

# …then swap one word
  -d '{"model": "seed-2.0-pro", "messages": [...]}'

Questions

Is GLM 5.3 or Seed 2.0 Pro better?

They grade within two points of each other (83.8 and 84.3), so pick on price and the benchmarks that match your work.

Which is cheaper, GLM 5.3 or Seed 2.0 Pro?

Seed 2.0 Pro: $0.50 in and $3.00 out per million tokens, against $0.90 and $4.00 through FullsendAI.

Which has the larger context window?

GLM 5.3, with 1,048,576 tokens.

Can I use both with one API key?

Yes, once they launch: both are coming soon, at the prices shown, and both will use the same FullsendAI key.

Model rankingsAll benchmarksCompare other models

Scores: LMArena (CC BY 4.0), SWE-bench, Scale AI SWE-Bench Pro, Terminal-Bench, and model makers’ published results where marked v. Prices are FullsendAI’s, per million tokens. Data as of Oct 28, 2026.