The two products sit at different layers. Tardis.dev sells the raw material. Aperiodic sells 220 point-in-time metrics built from it, as parquet (catalog), plus raw trades and top-of-book quotes for its three venues on Prime + Raw.
Where Tardis.dev wins
Say this first, because it decides most purchases.
- Raw L2 and L3. Tardis.dev offers tick-level L2 and L3 order books, trades, options chains and liquidations (tardis.dev, checked September 29, 2026). We do not sell raw order book updates at all.
- Tick-level replay. Its client libraries and HTTP API replay historical data tick by tick, with the raw replay API running to roughly six minutes behind real time (data FAQ, checked September 29, 2026). No aggregate replaces that, ours included.
- Exchange breadth. Tardis.dev lists 50+ spot and derivatives exchanges (tardis.dev, checked September 29, 2026). We cover three venues.
- History on its top plan. Yearly Business subscriptions include all history since 2019-03-30 (billing FAQ, checked September 29, 2026). Our Core and Pro tiers carry 4 years; Prime and Prime + Raw carry full history.
If one of these is the reason you are shopping, the rest of this page will not change your answer.
Where Aperiodic is the better alternative
You get the metric, not the pipeline. From trades, you would compute taker buy and sell volume, signed delta, size buckets and a toxicity score per bar, then validate it, then keep it point-in-time as the data revises. We ship those as columns.
The files are small. Here is one real preview file, pulled with no API key:
# Install the Aperiodic CLI into ~/.local/bin
mkdir -p "$HOME/.local/bin"
curl -fsSL https://raw.githubusercontent.com/aperiodic-io/cli/main/install.sh | INSTALL_DIR="$HOME/.local/bin" bash
export PATH="$HOME/.local/bin:$PATH"
aperiodic flow --preview --exchange binance-futures --symbol perpetual-BTC-USDT:USDT \
--interval 5m --timestamp exchange --start-date 2025-05-01 --end-date 2025-05-31 \
--output-dir ./data && echo "Saved to $PWD/data"It returns one parquet file: 8,928 rows, every 5-minute bar in May 2025 (31 × 288), with 36 order-flow metrics per bar, in 788,789 bytes (770 KiB). The columns include taker_buy_volume, volume_delta, flow_entropy, flow_toxicity_score, and buy and sell volume split into small, medium and large orders.
# pip install pandas pyarrow
import pandas as pd
df = pd.read_parquet("data/2025-05.parquet")
print(df.shape) # (8928, 37): time + 36 metricsYou can evaluate it before you pay. The preview needs no key and no account. Tardis.dev also offers free sample CSVs without an API key (tardis.dev, checked September 29, 2026), so this is not a point against them. What differs is what the sample contains: raw ticks there, finished features here.
The entry price is lower. Aperiodic self-serve runs from $79 to $1,249 a month billed yearly ($95 to $1,579 month to month) with no sales call (pricing). Tardis.dev has a $300 minimum order (tardis.dev, checked September 29, 2026) and does not offer discounts (billing FAQ, checked September 29, 2026). Self-serve Aperiodic plans carry a personal licence. Funds and desks need Institutional.
Raw data, for the venues we cover
Some questions do need the ticks: how trades printed against the quote, what happened in the seconds around a funding change, or a feature we don't publish. For those, the Prime + Raw plan adds raw trades, top-of-book quotes, mark and index price, funding rate and open interest for Binance, OKX and Hyperliquid perpetuals, under the same API key and symbols as the metrics. It is not a substitute for a full tick archive: we don't sell raw L2 order books, liquidations, options or other venues.
Side by side
| Tardis.dev | Aperiodic | |
|---|---|---|
| What arrives | Raw ticks: trades, quotes, L2/L3 book updates, options chains, liquidations | 220 computed metrics across 19 datasets; raw trades and top-of-book quotes on Prime + Raw |
| Venues | 50+ spot and derivatives exchanges | Binance futures, OKX perps, Hyperliquid perps |
| Granularity | Every tick, with replay | 1m to 1d self-serve; 15s/30s on Institutional |
| History | All since 2019-03-30 on yearly Business; 4 years on yearly Academic, Solo, Pro | 4 years on Core and Pro; full history on Prime and above |
| One month, BTC perp | Raw trades and book updates you aggregate yourself | 770 KiB parquet, 36 flow metrics at 5m (measured on this page) |
| Try before paying | Free sample CSVs, no key | Preview slice as parquet, no key |
| Entry price | $300 minimum order, no discounts | $79/month billed yearly ($95 month to month), personal licence |
| API keys (entry plans) | 1 key, 1 source IP (Solo, Academic, Pro) | Per plan; see pricing |
| Built for | Execution research, book reconstruction, market-making calibration | Signal research, backtests, ML features |
Tardis.dev facts checked September 29, 2026 against tardis.dev, the billing FAQ and the data FAQ. Pricing changes; check their site before you buy.
Migrating from Tardis.dev fields
If you already aggregate Tardis.dev CSVs (data types, checked September 29, 2026), this is where the work goes:
| Tardis.dev (per tick) | Aperiodic (per bar) |
|---|---|
trades.side, trades.amount | flow: taker_buy_volume, taker_sell_volume, volume_delta |
trades.price, trades.amount by size | flow: taker_buy_large_order_volume and the small and medium variants |
trades.price against the book | slippage: realized cost in bps |
derivative_ticker.funding_rate | funding |
derivative_ticker.open_interest | open_interest: open_interest, open_interest_notional, open_interest_pct_change |
derivative_ticker.mark_price, index_price | derivative_price, basis |
Which one to buy
Buy Tardis.dev if your edge depends on fills: queue position, maker fill simulation, latency-sensitive execution, or a venue outside Binance, OKX and Hyperliquid.
Buy Aperiodic if your question is about signals: cross-sectional factors, regime features, cost-aware backtests, ML inputs on perps at 1 minute or slower.
Many desks run both, raw ticks for execution research and aggregates for everything else.