# Comparison

URL: /docs/about/comparison/
Section: about
Tags: about, comparison

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Comparison Comprehensive comparison of Kida and Jinja2. Feature Matrix Feature Kida Jinja2 Compilation AST → AST String generation Rendering StringBuilder O(n) Generator yields Free-threading Native (PEP 703, Python 3.14t+) N/A Dependencies Zero markupsafe Block endings Unified &#123;% end %&#125; &#123;% endif %&#125;, etc. Pattern matching &#123;% match %&#125; N/A Pipeline |&gt; operator N/A Block caching &#123;% cache %&#125; N/A Async Native auto_await() Syntax Differences Block Endings Jinja2: &#123;% if condition %&#125; content &#123;% endif %&#125; &#123;% for item in items %&#125; {{ item }} &#123;% endfor %&#125; Kida (unified): &#123;% if condition %&#125; content &#123;% end %&#125; &#123;% for item in items %&#125; {{ item }} &#123;% end %&#125; Pipeline Operator Jinja2: {{ title | escape | upper | truncate(50) }} Kida: {{ title |&gt; escape |&gt; upper |&gt; truncate(50) }} Pattern Matching Jinja2: &#123;% if status == &quot;active&quot; %&#125; Active &#123;% elif status == &quot;pending&quot; %&#125; Pending &#123;% elif status == &quot;error&quot; %&#125; Error &#123;% else %&#125; Unknown &#123;% endif %&#125; Kida: &#123;% match status %&#125; &#123;% case &quot;active&quot; %&#125; Active &#123;% case &quot;pending&quot; %&#125; Pending &#123;% case &quot;error&quot; %&#125; Error &#123;% case _ %&#125; Unknown &#123;% end %&#125; Block Caching Jinja2: Not built-in (requires extensions) Kida: &#123;% cache &quot;sidebar-&quot; + user.id %&#125; {{ render_sidebar(user) }} &#123;% end %&#125; API Differences Filter Registration Jinja2: env.filters[&quot;double&quot;] = lambda x: x * 2 Kida: # Method style env.add_filter(&quot;double&quot;, lambda x: x * 2) # Decorator style @env.filter() def double(value): return value * 2 Markup Class Jinja2: Requires markupsafe: from markupsafe import Markup Kida: Built-in: from kida import Markup Environment Options Jinja2: env = Environment( loader=FileSystemLoader(&quot;templates&quot;), autoescape=select_autoescape(), extensions=[&quot;jinja2.ext.do&quot;], ) Kida: env = Environment( loader=FileSystemLoader(&quot;templates&quot;), autoescape=True, cache_size=400, fragment_ttl=300.0, ) Performance Single-Threaded Template Kida Jinja2 Speedup Minimal 0.94µs 3.21µs 3.4x Small 3.78µs 6.38µs 1.7x Medium 214µs 229µs 1.07x Large 2.27ms 2.48ms 1.09x Concurrent (Free-Threading) This is the real differentiator. Under concurrent workloads on Python 3.14t: Workers Kida Jinja2 Speedup 1 3.31ms 3.49ms 1.05x 2 2.09ms 2.51ms 1.20x 4 1.53ms 2.05ms 1.34x 8 2.06ms 3.74ms 1.81x Kida's advantage grows with concurrency because: Thread-safe design: Copy-on-write updates, no locks GIL independence: Declares _Py_mod_gil = 0 No shared mutable state: Renders use only local variables Jinja2 shows negative scaling at 8 workers (slower than 4 workers), indicating internal contention. See Performance Benchmarks for detailed measurements and methodology. When to Use Kida Choose Kida if you: Need free-threading support (Python 3.14t) Want zero dependencies Prefer unified block syntax Need built-in caching Want pattern matching in templates Value AST-native compilation When to Keep Jinja2 Keep Jinja2 if you: Need LaTeX/RTF output formats Use Jinja2-specific extensions Have heavy investment in Jinja2 tooling Need the sandboxed environment See Also Performance — Detailed benchmarks Architecture — How Kida works

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