{"slug":"pm-api-latency","title":"Best prediction market API, ranked by live latency and uptime","subtitle":"Warm price endpoint latency of five prediction market venue APIs from three regions, plus a live uptime panel that answers whether each API is up right now.","category":"Trading","metric":"API latency (price endpoint)","unit":"ms","status":"live","higherIsBetter":false,"value":101.069,"leader":{"name":"Polymarket","slug":"polymarket","value":101.069},"rankings":[{"name":"Polymarket","slug":"polymarket","ms":{"p50":101.069,"p90":221.012,"p99":247.97,"mean":105.928},"successRate":100,"sampleSize":51832},{"name":"Manifold","slug":"manifold","ms":{"p50":118.406,"p90":314.198,"p99":942.467,"mean":157.04},"successRate":99.946,"sampleSize":37020.4},{"name":"Kalshi","slug":"kalshi","ms":{"p50":125.019,"p90":365.407,"p99":527.923,"mean":157.25},"successRate":100,"sampleSize":51833},{"name":"Limitless","slug":"limitless","ms":{"p50":136.028,"p90":321.946,"p99":1143.97,"mean":188.739},"successRate":99.9768,"sampleSize":51824},{"name":"Myriad","slug":"myriad","ms":{"p50":248.186,"p90":1388.07,"p99":2366.42,"mean":590.16},"successRate":97.56240000000001,"sampleSize":51785.1}],"sparkline":[123.85,123.886,123.999,124.452,124.373,124.028,123.99,123.954,123.492,123.69,124.23,124.137,115.895,104.854,96.6727,97.4938,96.8373,94.7126,93.9338,92.6716,92.6025,92.1165,91.9393,90.9513,90.6304,91.0938,91.8773,92.3611,92.529,92.7838,92.8888,92.6657,92.7696,91.9242,91.5516,90.7609,90.7723,89.9546,90.2331,90.0293,90.2331,92.3263,97.0122,107.439,111.876,110.124,111.129,113.023,116.745,115.613,110.896,106.679,107.203,108.949,109.159,109.532,111.634,113.481,116.006,117.028,113.085,99.3984,93.1138,91.9076,93.6219,97.1784,99.1711,99.1644,99.8961,106.002,106.873,108.529,107.41],"sampleSize":244294.5,"asOf":"2026-06-16T15:41:31.340Z","headline":"Polymarket leads api latency (price endpoint) at 101 ms (p50, 24h) on Best prediction market API, ranked by live latency and uptime.","quote":"Polymarket leads api latency (price endpoint) at 101 ms (p50, 24h) on Best prediction market API, ranked by live latency and uptime. Source: OpenChainBench (https://openchainbench.com/benchmarks/pm-api-latency).","pageUrl":"https://openchainbench.com/benchmarks/pm-api-latency","ogImage":"https://openchainbench.com/api/og/pm-api-latency","source":"https://github.com/MobulaFi/mobula-monorepo/tree/main/miniapps/pm-rate-limits","methodology":["Price endpoint per venue. Polymarket: CLOB `/midpoint`. Kalshi: `/markets/{ticker}`. Limitless: `/markets/{slug}`. Manifold: `/v0/market/{id}`. Myriad: `/markets/{slug}`. This is the hot path of real integrations: one market, one quote, polled in a loop.","Warm probes every 5s (7s on Manifold, whose API sits behind max-age=5 plus stale-while-revalidate=10) from us-east, eu-west and sgp over a keep alive pool. A separate cold connect probe once per minute records the TCP plus TLS handshake a brand new client pays.","Every sample carries a cache flag read from cf-cache-status, x-cache and age headers. Latency aggregates exclude cache hits: a CDN hit measures the nearest edge, not the venue's API, and including Manifold's residual cache hits would flatter it by design.","Uptime is the average of a per venue, per region health gauge (pmapi_health) computed by the harness from probe outcomes. 100 percent means every probe cycle in the window succeeded from that region. The 24h and 7d panels below are the live answer to whether each API is up.","Outcome classification: ok, timeout (8s), http_4xx, http_5xx, throttled, probe_invalid, net_error. probe_invalid covers failures that are our pin's fault, such as a market that resolved intraday; those are excluded from both latency and uptime. The pinned market is re selected daily at 00:00 UTC and immediately on probe_invalid.","Division of labor with the sibling benches: how each venue behaves as request rates climb, including throttle onset and 429 handling, is measured in pm-rate-limits (bench 037). How fresh third party data providers relay Polymarket data is measured in pm-data-freshness (bench 032). This bench ranks the venues' own APIs on latency and uptime at a polite request rate.","Myriad's origin is a single region US East deployment behind Heroku, so its latency from eu-west and sgp is dominated by geography. Reported as measured, called out per region.","All five venues are probed by the same open source harness as bench 037, from the same processes, so the two benches share one probe budget and one identifying User-Agent: `OpenChainBench/1.0 (+https://openchainbench.com/methodology; contact@mobula.io)`. We publish latency and uptime measurements only, never market data.","Regions: us-east, eu-west, sgp (Railway). Histogram buckets 25ms to 10s."],"license":"CC-BY-4.0"}