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GLM-5.3 vs Claude Opus 5
Claude Opus 5 scores higher than GLM-5.3 on all 3 public leaderboards that rate both. On the ArtificialWatch Index, which takes the median of each model's percentile across the boards that score it, GLM-5.3 is at 48.1 and Claude Opus 5 at 73.9 (out of 100). On each maker's API, GLM-5.3 costs $1.40 / $4.40 per 1M tokens (input / output) and Claude Opus 5 $5 / $25.
Scores as published by each board; table composed November 12, 2026.
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Leaderboard by leaderboard
| Board | GLM-5.3 | Claude Opus 5 | Higher |
|---|---|---|---|
| LMArena Elo (community votes) | 1,622.3 | 1,691 | Claude Opus 5 |
| SimpleBench AVG@5 % (private set) | 66.2 | 80.6 | Claude Opus 5 |
| Epoch AI Epoch Capabilities Index (ECI) · many benchmarks on one scale | 157.1 | 164.7 | Claude Opus 5 |
Raw scores are each board's own scale, so compare within a row, not across rows. Full table: the bench index.
For coding
On the ArtificialWatch coding index, GLM-5.3 is at 51.5 (#20 of 47) and Claude Opus 5 at 85 (#7). Claude Opus 5 scores higher on both coding boards that rate them.
| Coding board | GLM-5.3 | Claude Opus 5 |
|---|---|---|
| LMArena · Coding | 1,499 | 1,531.9 |
| Vals Vibe Code Bench | 78.1 | 88.4 |
GLM-5.3 at a glance
- Developer
- Zhipu AI
- Status
- Live since August 14, 2026
- API price
- $1.40 input / $4.40 output per 1M tokens · Z.AI, glm-5.3
- Context window
- 1M tokens
Live - same 743B base as 5.2, every gain from post-training · tops CyberGym · open weights on Hugging Face (zai-org/GLM-5.3, 141 safetensors files, public when we read it Sep 25; repo created Aug 25) · Anthropic research (Sep 29): builds end-to-end exploits near Claude Mythos Preview's rate (ExploitBench 50 of 410 vs 56 of 410), and its safeguards fell to simple bypasses 64-100% of the time · Epoch AI report (Oct 29): built one-click file-reading exploits for all six Firefox releases Sep 17-Oct 26 from published-but-unshipped fixes, about $1,000 each, with no refusals at any provider.
Epoch AI: open-weight GLM 5.3 built working Firefox exploits from security fixes that had not shipped yet, for about $1,000 each
2026-10-30 · An open-weight model can now turn browser security fixes that are public but not yet shipped into working exploits on its own, according to a report Epoch AI published October 29.
Anthropic: open-weights GLM-5.3 nearly matches Claude Mythos Preview at building exploits, and its safeguards are easy to strip
2026-09-29 · Anthropic published research on September 29 testing Z.ai's GLM-5.3, an open-weights model anyone can download, on offensive cyber tasks. Its finding: GLM-5.3 can build working end-to-end exploits at close to the rate of Claude Mythos Preview, the model Anthropic released only to vetted defenders.
Claude Opus 5 at a glance
- Developer
- Anthropic
- Status
- Live since July 24, 2026
- API price
- $5 input / $25 output per 1M tokens · Anthropic, claude-opus-5
- Context window
- 1M tokens
Live — detected 16:51 UTC Jul 24, alert fired 61s later · superseded by Opus 5.5 on Sep 22 and moved to Anthropic's legacy list; still served at $5/$25, which is now MORE than its successor.
Claude Opus 5 is live — we detected it at 16:51 UTC and had alerts out 61 seconds later
2026-07-24 · Anthropic's Claude Opus 5 went live on the public API today. Our checkers saw the id appear at 16:51:33 UTC, confirmed it on the next 60-second sweep, and the alert blast went out at 16:52:34 — sixty-one seconds from first sighting to inbox.
GLM-5.3 vs Claude Opus 5: quick answers
Which is better, GLM-5.3 or Claude Opus 5?
It depends on what you measure. Claude Opus 5 scores higher than GLM-5.3 on all 3 public leaderboards that rate both. Claude Opus 5's widest lead is on SimpleBench. On the ArtificialWatch Index, which takes the median of each model's percentile across the boards that score it, GLM-5.3 is at 48.1 and Claude Opus 5 at 73.9 (out of 100).
Which is newer, GLM-5.3 or Claude Opus 5?
GLM-5.3. It went live on August 14, 2026, 21 days after Claude Opus 5 (July 24, 2026).
Which is cheaper, GLM-5.3 or Claude Opus 5?
GLM-5.3 is cheaper on both input and output. On each vendor's own API, GLM-5.3 is $1.40 input / $4.40 output per million tokens and Claude Opus 5 is $5 input / $25 output per million tokens. Prices as published in the models.dev catalog, as of 2026-11-12.
Which has the bigger context window, GLM-5.3 or Claude Opus 5?
Neither. Both take 1M tokens.
How do GLM-5.3 and Claude Opus 5 compare for coding?
On the ArtificialWatch coding index, GLM-5.3 is at 51.5 (#20 of 47) and Claude Opus 5 at 85 (#7). Claude Opus 5 scores higher on both coding boards that rate them.
Who makes GLM-5.3 and Claude Opus 5?
GLM-5.3 is from Zhipu AI; Claude Opus 5 is from Anthropic.
Where do these numbers come from?
Each score is the leaderboard's own published figure, read by ArtificialWatch (table composed November 12, 2026). Boards measure different things, so raw scores are only comparable within a row.
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