GLM-5.3 vs Claude Sonnet 5.5
Official GLM (Z.ai) and Anthropic API prices and LMArena scores, checked 2026-10-29. Add up to 2 more models to compare 4.
GLM-5.3 costs less; Claude Sonnet 5.5 wins more LMArena tasks.
GLM-5.3 is 1.4x cheaper on input and 2.3x cheaper on output. Claude Sonnet 5.5 scores 54 points higher for coding; GLM-5.3 scores 7 points higher for chat. Across 6 shared LMArena tasks, Claude Sonnet 5.5 leads 4 to 2. A medium month (20M input + 5M output tokens) costs $50 on GLM-5.3 and $90 on Claude Sonnet 5.5.
- Pick GLM-5.3 if you want the lower bill ($50 vs $90 for a medium month) or you care most about chat (+7).
- Pick Claude Sonnet 5.5 if you care most about coding (+54), agent tasks (+34) and creative writing (+16) or you reuse long prompts (cached input $0.10 vs $0.26).
Medium: 20M input + 5M output tokens a month at list price (short-context rate, no caching or batch discounts).
Marked side is better: lower for prices, higher for context and scores. Bars are scaled to the larger of the two.
| Spec | GLM-5.3 | Claude Sonnet 5.5 |
|---|---|---|
| Price per 1M tokens | ||
| Input | $1.40 | $2 |
| Cached input | $0.26 | $0.10 |
| Output | $4.40 | $10 |
| Blend 3:1 | $2.15 | $4 |
| Sample month, medium | $50 | $90 |
| Context | ||
| Context window | Not published | 1M tokens |
| Quality (LMArena, out of 100) | ||
| Coding | 31/100 #20 of 50 | 85/100 #3 of 50 |
| Chat | 25/100 #14 of 51 | 18/100 #16 of 51 |
| Creative writing | 15/100 #13 of 51 | 31/100 #10 of 51 |
| Roleplay and characters | 3/100 #16 of 51 | 1/100 #17 of 51 |
| Reasoning and math | 42/100 #12 of 51 | 57/100 #8 of 51 |
| Vision | Not ranked | 22/100 #16 of 33 |
| Long documents | Not ranked | Not ranked |
| Cheap bulk and agents | 47/100 #22 of 34 | 81/100 #2 of 34 |
| Details | ||
| Provider | GLM (Z.ai) | Anthropic |
| API model id | glm-5.3 | claude-sonnet-5.5 |
| Notes | None | 5-minute cache writes $2.50. |
| Sources | ||
| Last checked | 2026-10-29 | 2026-10-29 |
| Official pricing | GLM (Z.ai) pricing | Anthropic pricing |
Plans from data checked hourly against each vendor's official pricing page. Vendors state limits in different units, so we quote them as published. Team and enterprise plans are per seat.
API prices in USD per 1M tokens from each provider's official pricing page. Blend 3:1 = (3 x input + output) / 4. Sample month = stated input and output tokens at the list price, no caching. Quality: relative score out of 100 on each LMArena leaderboard (100 = top model we price on that board, n/a = not ranked there), data licensed CC BY 4.0. See how we pick.
Where each one ranks on LMArena
Relative score out of 100 on each leaderboard (100 = the top model we price there), with the rank among the models from our API price table that appear on that board.
- Coding (Code Arena): GLM-5.3 #20 of 50 (31/100), Claude Sonnet 5.5 #3 of 50 (85/100)
- Chat (Text Arena): GLM-5.3 #14 of 51 (25/100), Claude Sonnet 5.5 #16 of 51 (18/100)
- Creative writing (Text Arena creative writing): GLM-5.3 #13 of 51 (15/100), Claude Sonnet 5.5 #10 of 51 (31/100)
- Roleplay and characters (Text Arena multi-turn): GLM-5.3 #16 of 51 (3/100), Claude Sonnet 5.5 #17 of 51 (1/100)
- Reasoning and math (Text Arena math): GLM-5.3 #12 of 51 (42/100), Claude Sonnet 5.5 #8 of 51 (57/100)
- Vision (Vision Arena): GLM-5.3 not ranked, Claude Sonnet 5.5 #16 of 33 (22/100)
- Long documents (Document Arena): GLM-5.3 not ranked, Claude Sonnet 5.5 not ranked
- Cheap bulk and agents (Agent Arena): GLM-5.3 #22 of 34 (47/100), Claude Sonnet 5.5 #2 of 34 (81/100)
Pricing details from the official pages
GLM-5.3 lists $1.40 input, $4.40 output, $0.26 cached input per 1M tokens on GLM (Z.ai) pricing. Claude Sonnet 5.5 lists $2 input, $10 output, $0.10 cached input per 1M tokens on Anthropic pricing. Prices checked 2026-10-29.
- Claude Sonnet 5.5: 5-minute cache writes $2.50.
Sample monthly bill at list price, no caching: Light (2M input + 0.5M output tokens): $5 vs $9. Medium (20M input + 5M output tokens): $50 vs $90. Heavy (200M input + 50M output tokens): $500 vs $900.
FAQ
Is GLM-5.3 cheaper than Claude Sonnet 5.5?
GLM-5.3 costs $1.40 input and $4.40 output per 1M tokens; Claude Sonnet 5.5 costs $2 and $10. For a medium month (20M input + 5M output tokens) GLM-5.3 is cheaper: $50 vs $90.
Which is better for coding, GLM-5.3 or Claude Sonnet 5.5?
On LMArena's Code Arena GLM-5.3 scores 31/100 (#20 of 50) and Claude Sonnet 5.5 85/100 (#3 of 50), so Claude Sonnet 5.5 is ahead by 54 points.
Which has the bigger context window?
GLM-5.3: n/a. Claude Sonnet 5.5: 1M tokens.
How much do GLM-5.3 and Claude Sonnet 5.5 cost per month?
Light (2M input + 0.5M output tokens): $5 vs $9. Medium (20M input + 5M output tokens): $50 vs $90. Heavy (200M input + 50M output tokens): $500 vs $900. Pick your own token counts in the plan vs API calculator.
Where do these numbers come from?
Prices come from each provider's official pricing page, checked daily. Quality is the relative score on the LMArena leaderboard dataset, licensed CC BY 4.0. Where a model is not ranked we show n/a.