Part of Best LLM for Coding
Best LLM for Code Completion
Claude Sonnet 5.5 ranks first for Code Completion as of October 21, 2026.[1][2][3] It scores 91.37% on LiveBench Coding (#1 of 59), an objective evaluation of code generation and completion. Claude Opus 5.5 is the next-ranked alternative. It achieves #1 rank on LMArena WebDev coding with Elo 1807, the highest human preference score in the evaluation, though it trails Sonnet 5.5 on objective LiveBench Coding at 89.25% (#2 of 59).
- Best open-weight pick: Kimi K3 (#4)
- Compare Claude Sonnet 5.5 vs Claude Opus 5.5 →
About this recommendation
- Updated
- Evidence through
- Sources
- 9
- Revision
- v116
Decision audit
Why this result
Inspect the inputs and the computed order behind the recommendation.
Models screened
24
live candidates
Evaluation feeds
4
task-weighted
Winner coverage
83%
intended feed weight
Largest provider share
3 of 8
Anthropic
Anthropic: Claude Sonnet 5.5 leads the measured task comparison with 2 independent evaluation families. Community volume, release age and usage popularity add no ranking points. This category also weights its stated price or context criteria.
Real-world track record is still developing. The recommendation can lead on independent measurements while practitioner reports accumulate.
Sources evaluated
These are the weights used in scoring. Missing measurements are omitted from each model’s average. A feed with no result for any model released in the last 60 days is stale and does not score until it catches up.
| Evaluation feed | Weight | Winner result | Field measured |
|---|---|---|---|
| LiveBench Coding (2026-06-25)Observed 2026-10-18 · evaluation date not supplied · claude-sonnet-5-5-max-effortfailing; last successful check 2026-10-18 | 40% | #1 | 24/24 |
| LMArena WebDevObserved 2026-10-19 · evaluation date not supplied · xhigh effort | 33% | #3 | 24/24 |
| price weight | 27% | 45/100 | 24/24 |
| Aider Polyglotstale | 0% | no current result | 0/24 |
Provider concentration
Each exact model is scored separately; provider identity is not a ranking input.
- Anthropic3 models
- Z.ai2 models
- deepseek1 model
- Moonshot AI1 model
- OpenAI1 model
Decision table
Every published model is shown in computed order. Practitioner sources are distinct community threads, not the citations repeated in the prose below.
Anthropic · coverage 83%
#1 LiveBench Coding · #3 LMArena WebDev
Anthropic · coverage 83%
#1 LMArena WebDev · #2 LiveBench Coding
Anthropic · coverage 83%
#3 LiveBench Coding · #5 LMArena WebDev
Moonshot AI · coverage 83%
#12 LiveBench Coding · #12 LMArena WebDev
deepseek · coverage 83%
#18 LiveBench Coding · #20 LMArena WebDev
Z.ai · coverage 83%
#19 LiveBench Coding · #23 LMArena WebDev
Z.ai · coverage 83%
#22 LiveBench Coding · #22 LMArena WebDev
OpenAI · coverage 83%
#4 LMArena WebDev · #16 LiveBench Coding
Task score averages the available, task-weighted measurements. Benchmark positions compare models matched to our catalog. Models measured by at least two independent evaluator families are considered first. Missing tests, practitioner report counts, popularity and release age add no points. Coverage describes evidence breadth, not a probability of correctness. Scores within two points are shown as close under this policy; this is not a statistical confidence interval. When the leading scores are that close, the model measured by more evaluator families ranks first.
- 01
Claude Sonnet 5.5Anthropic · $2 in / $10 out per M tokens · 1M context
Claude Sonnet 5.5 scores 91.37% on LiveBench Coding (#1 of 59), an objective evaluation of code generation and completion.
Best when: Its strongest result for this task is on LiveBench Coding, which measures code generation and completion.No practitioner reports are linked yet, so no cautions are listed. Absence of reports is not evidence of reliability.
- 02
Claude Opus 5.5Anthropic · $4 in / $20 out per M tokens · 1M context
Claude Opus 5.5 achieves #1 rank on LMArena WebDev coding with Elo 1807, the highest human preference score in the evaluation, though it trails Sonnet 5.5 on objective LiveBench Coding at 89.25% (#2 of 59).
Best when: Prioritize for autocomplete when human preference rankings drive your quality metric, as it tops the LMArena WebDev leaderboard.No practitioner reports are linked yet, so no cautions are listed. Absence of reports is not evidence of reliability.
- 03
Claude Fable 5.1Anthropic · $10 in / $50 out per M tokens · 1M context
Claude Fable 5.1 scores 86.38% on LiveBench Coding (#3 of 59), an objective evaluation of code generation and completion.
Best when: Its strongest result for this task is on LiveBench Coding, which measures code generation and completion.No practitioner reports are linked yet, so no cautions are listed. Absence of reports is not evidence of reliability.
- 04
Kimi K3Moonshot AI · $0.24 in / $11.94 out per M tokens · 1.0M context · open-weight
Kimi K3 ranks #12 of 99 on LMArena's WebDev coding arena (Elo 1655), a leaderboard built from blind human preference votes on coding tasks.
Best when: Its strongest result for this task is on LMArena WebDev, which measures practical, real-world coding quality.No practitioner reports are linked yet, so no cautions are listed. Absence of reports is not evidence of reliability.
- 05
DeepSeek V4.1 Flashdeepseek · $0.049 in / $0.38 out per M tokens · 1.0M context · open-weight
DeepSeek V4.1 Flash scores 80.04% on LiveBench Coding (#18 of 59), an objective evaluation of code generation and completion.
Best when: Its strongest result for this task is on LiveBench Coding, which measures code generation and completion.No practitioner reports are linked yet, so no cautions are listed. Absence of reports is not evidence of reliability.
- 06
GLM 5.2Z.ai · $0.034 in / $7 out per M tokens · 1.0M context · open-weight
GLM 5.2 scores 79.65% on LiveBench Coding (#19 of 59), an objective evaluation of code generation and completion.
Best when: Its strongest result for this task is on LiveBench Coding, which measures code generation and completion.No practitioner reports are linked yet, so no cautions are listed. Absence of reports is not evidence of reliability.
- 07
GLM 5.3 FlashZ.ai · $0.041 in / $0.12 out per M tokens · 1.0M context · open-weight
GLM 5.3 Flash ranks #22 of 99 on LMArena's WebDev coding arena (Elo 1607), a leaderboard built from blind human preference votes on coding tasks.
Best when: Its strongest result for this task is on LMArena WebDev, which measures practical, real-world coding quality.No practitioner reports are linked yet, so no cautions are listed. Absence of reports is not evidence of reliability.
- 08
GPT-6.1 SolOpenAI · $2 in / $10 out per M tokens · 1.1M context
GPT-6.1 Sol ranks #4 of 99 on LMArena's WebDev coding arena (Elo 1753), a leaderboard built from blind human preference votes on coding tasks.
Best when: Its strongest result for this task is on LMArena WebDev, which measures practical, real-world coding quality.No practitioner reports are linked yet, so no cautions are listed. Absence of reports is not evidence of reliability.
Frequently asked
- What is the best model for Code Completion?
- Claude Sonnet 5.5 ranks first as of October 21, 2026. Claude Sonnet 5.5 scores 91.37% on LiveBench Coding (#1 of 59), an objective evaluation of code generation and completion.[1]
- What is the best alternative to Claude Sonnet 5.5?
- Claude Opus 5.5 ranks second. Claude Opus 5.5 achieves #1 rank on LMArena WebDev coding with Elo 1807, the highest human preference score in the evaluation, though it trails Sonnet 5.5 on objective LiveBench Coding at 89.25% (#2 of 59).[2][3]
- Which open-weight model ranks highest for Code Completion?
- Kimi K3 is the highest-ranked open-weight model, at #4. Kimi K3 ranks #12 of 99 on LMArena's WebDev coding arena (Elo 1655), a leaderboard built from blind human preference votes on coding tasks.[4]
Sources
- 1
“Within the 59 catalog models matched to this evaluation: Scores 91.37% on LiveBench Coding (#1 of 59), an objective evaluation of code generation and completion.”
LiveBench Coding · Benchmark · Oct 18, 2026 - 2
“Within the 99 catalog models matched to this evaluation: Ranks #1 of 99 on LMArena's WebDev coding arena (Elo 1807), a leaderboard built from blind human preference votes on coding tasks.”
LMArena WebDev (coding) arena · Benchmark · Oct 19, 2026 - 3
“Within the 59 catalog models matched to this evaluation: Scores 89.25% on LiveBench Coding (#2 of 59), an objective evaluation of code generation and completion.”
LiveBench Coding · Benchmark · Oct 18, 2026 - 4
“Within the 99 catalog models matched to this evaluation: Ranks #12 of 99 on LMArena's WebDev coding arena (Elo 1655), a leaderboard built from blind human preference votes on coding tasks.”
LMArena WebDev (coding) arena · Benchmark · Oct 19, 2026 - 5
“Within the 59 catalog models matched to this evaluation: Scores 86.38% on LiveBench Coding (#3 of 59), an objective evaluation of code generation and completion.”
LiveBench Coding · Benchmark · Oct 18, 2026 - 6
“Within the 59 catalog models matched to this evaluation: Scores 80.04% on LiveBench Coding (#18 of 59), an objective evaluation of code generation and completion.”
LiveBench Coding · Benchmark · Oct 18, 2026 - 7
“Within the 59 catalog models matched to this evaluation: Scores 79.65% on LiveBench Coding (#19 of 59), an objective evaluation of code generation and completion.”
LiveBench Coding · Benchmark · Oct 18, 2026 - 8
“Within the 99 catalog models matched to this evaluation: Ranks #22 of 99 on LMArena's WebDev coding arena (Elo 1607), a leaderboard built from blind human preference votes on coding tasks.”
LMArena WebDev (coding) arena · Benchmark · Oct 19, 2026 - 9
“Within the 99 catalog models matched to this evaluation: Ranks #4 of 99 on LMArena's WebDev coding arena (Elo 1753), a leaderboard built from blind human preference votes on coding tasks.”
LMArena WebDev (coding) arena · Benchmark · Oct 19, 2026
Rankings synthesized from community evidence and open benchmarks. See methodology. Not driven by vendor marketing.