> ## Documentation Index
> Fetch the complete documentation index at: https://docs.placematic.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Can I run Google and HERE in parallel?

> You should, during migration. And you may want to stay that way permanently.

# Can I run Google and HERE in parallel?

**Short answer:** Yes, and you should — both as a migration technique and, for many products, as the permanent architecture.

## During migration: shadow-write

**The primary serves the user. The shadow result is discarded.**

<Warning>
  The shadow call must be **asynchronous and fire-and-forget.** If it can affect production latency, you have built a second point of failure to test the first.
</Warning>

**Feature-flag per endpoint, not per user.**

A percentage rollout across a routing engine gives you two populations with different route quality and no way to attribute an incident. A rollback should be one flag, one surface, no deploy.

**Compare offline, against ground truth.** Not against each other. Two wrong answers can agree.

**Keep both live for at least one full business cycle after cutover.** Two invoices for a month is cheaper than one incident. You're not testing the happy path — you're waiting for the edge case that only occurs on the last Friday of the month.

## Permanently: the hybrid

<Info>
  **The best architecture for many products is both.**

  Google for consumer-facing place search and autocomplete. HERE for routing, matrix operations, batch geocoding, and truck constraints.

  Nothing requires vendor monogamy, and the split follows the strengths cleanly.
</Info>

**Why:** Google's business POI database — hours, reviews, photos, categories — is categorically better than HERE's. Placematic sells HERE. We'd rather you know now than after a migration.

**Why:** HERE expresses commercial vehicle constraints that Google does not, and does not expose the underlying road attributes either. You cannot implement them yourself.

**Document the split as a decision**, in writing, before someone frames a deliberate hybrid as a failed migration.

## What running both costs

Two contracts. Two invoices. Two support paths. Two free tiers that don't pool.

Real overhead. For a small team it may exceed the benefit. For a fleet platform where the map is customer-facing and the routing is safety-critical, it does not.

## The one thing you must not do

<Warning>
  **Never fail over from constrained HERE truck routing to unconstrained Google routing.**

  It produces a route a truck cannot drive, in a system that believes it degraded gracefully.

  **Refuse to route instead.** A dispatcher calling operations is a better outcome than a driver following a route through a low bridge.
</Warning>

## What genuinely fails over

* **Tiles.** A CDN with a secondary origin. Users see a map.
* **Geocoding.** A cached result, or a stale coordinate with a warning.
* **Serviceability checks.** Materialized polygons in your own database. Neither vendor being up is relevant.

## Common misconceptions

**"A hybrid is a failed migration."**
It's a decision. Write it down before someone else characterizes it.

**"Dual-running is expensive."**
Shadow traffic doubles call volume for its duration. Budget for it, and say so.

**"I'll compare Google's answer to HERE's."**
Compare both against telematics ground truth. Two wrong answers can agree.

**"Percentage rollout is standard practice."**
Standard for buttons. Wrong for routing engines.

## Related

<CardGroup cols={2}>
  <Card title="Google Migration Architecture" href="/architecture/google-migration-architecture">
    Shadow-write, per-endpoint flags, tested rollback.
  </Card>

  <Card title="Migrating One Endpoint" href="/examples/google-migration">
    The shadow implementation, in code.
  </Card>

  <Card title="HERE vs Google Maps" href="/comparisons/here-vs-google-maps">
    Where each genuinely wins.
  </Card>

  <Card title="How do I validate the migration?" href="/faq/how-do-i-validate-the-migration">
    Ground truth, distributions, gates.
  </Card>
</CardGroup>

***

Need production HERE API keys or implementation support? Placematic is an official HERE Technologies reseller and implementation partner. [Talk to us](https://placematic.com/contact/).