PredictIt leads on both live benchmarks. PredictIt wins on Prediction market API rate limits, tested with a daily ramp (117 ms vs 127 ms), Best prediction market API, ranked by live latency and uptime (117 ms vs 126 ms). Data as of 2026-10-27 UTC.
CFTC-regulated US prediction market exchange. REST trade API (trade-api/v2) with documented per-tier rate limits; the market data WebSocket requires authentication.
CFTC-regulated US political prediction market. Real-money contracts on US elections, legislation and political events. REST API returns market data without authentication; rate-limited to 5 requests per minute.
| Provider | Warm book latency | Cold connect |
|---|---|---|
| Kalshi | 127 ms | 8 ms |
| PredictIt | 117 ms | 11 ms |
Ramp tiers stay well inside documented budgets where they exist, at most 7 percent of Polymarket's published book allowance, and every run aborts at the first sign of sustained errors. This benchmark measures throttle onset behaviour at polite request rates, not maximum venue throughput.
| Provider | API latency (price endpoint) | Uptime 24h | Uptime 7d | Cold connect |
|---|---|---|---|---|
| Kalshi | 126 ms | 100.0% | 99.9% | 8 ms |
| PredictIt | 117 ms | 66.7% | 66.5% | 11 ms |
Uptime here means our probes succeeded from three specific regions at a polite request rate. A venue can be up for us and degraded for you, especially during regional network incidents, and a brief blip between probe cycles can go unrecorded. Treat the panel as a measured signal, not a guarantee.
Kalshi and PredictIt are compared on 2 shared OpenChainBench benchmarks. PredictIt leads on Prediction market API rate limits, tested with a daily ramp. See the live table on this page for every metric.
On the Prediction market API rate limits, tested with a daily ramp benchmark, PredictIt leads at 117 ms versus Kalshi at 127 ms. Live measurement is updated continuously by the OpenChainBench harness.
Every benchmark on this page uses the same open methodology, published at https://openchainbench.com/methodology. Data is CC-BY-4.0. Measurement harnesses are MIT-licensed.
Auto-generated pairs require: both providers in the same benchmark for seven consecutive days, at least 1000 samples per provider, observable third-party search demand, and a public /products/[slug] page on OCB. Editorially curated pairs (like this one) may publish early when search demand is high and data is accruing; panels with fewer than 100 samples are shown as provisional. The full pair ledger is versioned in the public repo.