Redis Cloud vs AWS ElastiCache vs Google Cloud Memorystore: Real Managed Redis Cost at 100 GB in 2026
Prices checked: October 2, 2026.
Short answer
For a 100 GB high-availability Redis dataset (primary plus replica) running all month:
| Option | Monthly cost | Label |
|---|---|---|
| Memorystore for Redis Standard, 125 GiB (M5) | $2,737.50 | ILLUSTRATIVE from OFFICIAL rates |
| Memorystore Standard, exactly 100 GiB (M4) | $2,555.00 | ILLUSTRATIVE from OFFICIAL rates |
| ElastiCache for Valkey, 2× cache.r7g.4xlarge (tight fit) | $2,038.16 | ILLUSTRATIVE |
| ElastiCache for Valkey, 2 shards × 2 nodes r7g.4xlarge (headroom) | $4,076.32 | ILLUSTRATIVE |
| ElastiCache for Redis OSS, same 4 nodes | $5,095.40 | ILLUSTRATIVE |
| ElastiCache Serverless for Valkey (storage alone) | $6,132 + ECPUs | ILLUSTRATIVE from OFFICIAL rates |
| Redis Cloud Pro, 100 GB | No public list price; calculator or sales | QUOTE-ONLY |
Memorystore has the simplest and often lowest realistic price for 100 GB with HA. Your replica is included in the Standard-tier GB rate, and there's no node-size puzzle. ElastiCache on Valkey can undercut it on paper, but only if you squeeze 100 GB into nodes with very little headroom.
Native billing units
| Service | Billed on | Rate | Label |
|---|---|---|---|
| Memorystore for Redis Basic (no replica), us-central1 | Provisioned GiB-hour | M4 (36–100 GiB): $0.019; M5 (>100 GiB): $0.016 | OFFICIAL |
| Memorystore for Redis Standard (HA replica), us-central1 | Provisioned GiB-hour | M4: $0.035; M5: $0.030 | OFFICIAL |
| Memorystore Standard with read replicas | Provisioned GiB-hour × nodes | M4: $0.019; M5: $0.016, per node | OFFICIAL |
| ElastiCache node-based (us-east-1) | Node-hour | cache.r7g.4xlarge (105.81 GiB): $1.745 Redis OSS; Valkey priced 20% lower ($1.396) | REPORTED price; OFFICIAL 20% Valkey discount |
| ElastiCache Serverless for Valkey | GB-hour stored + ECPUs | $0.084/GB-hour; $0.0023 per million ECPUs | OFFICIAL |
| ElastiCache backup storage | GiB-month | $0.085 | OFFICIAL |
| ElastiCache cross-AZ traffic | GB | $0.01 | OFFICIAL |
| Redis Cloud Essentials | Fixed plan | From $5/month; standard plans up to 12 GB; Redis Flex plans (RAM + SSD) up to 100 GB at 20,000 ops/sec | OFFICIAL (plan sizes); prices not listed |
| Redis Cloud Pro | Hourly, sized to dataset, throughput and HA | From $0.014/hour, $200/month minimum | OFFICIAL (floor); 100 GB price QUOTE-ONLY |
How 100 GB maps to each billing unit
Memorystore: priced per provisioned GiB, replica included
Memorystore's Standard tier price already covers the HA replica. One pricing detail stands out: above 100 GiB the per-GiB rate drops from $0.035 (M4) to $0.030 (M5).
| Provisioned size | Tier | Monthly |
|---|---|---|
| 100 GiB | M4 | 100 × $0.035 × 730 = $2,555.00 |
| 101 GiB | M5 | 101 × $0.030 × 730 = $2,211.90 |
| 125 GiB (20% headroom) | M5 | 125 × $0.030 × 730 = $2,737.50 |
A 101 GiB instance costs $343 less a month than a 100 GiB one. If you need about 100 GiB, provision just over the M5 line.
ElastiCache: priced per node, so you buy memory in steps
A cache.r7g.4xlarge has 105.81 GiB. AWS recommends reserving part of node memory for overhead, so 100 GB of data on one node leaves almost no buffer. Two layouts:
| Layout | Nodes | Valkey | Redis OSS |
|---|---|---|---|
| Tight: 1 shard, primary + replica, r7g.4xlarge | 2 | 2 × $1.396 × 730 = $2,038.16 | 2 × $1.745 × 730 = $2,547.70 |
| Headroom: 2 shards × (primary + replica), r7g.4xlarge | 4 | $4,076.32 | $5,095.40 |
The jump from 2 to 4 nodes doubles the bill. Memorystore's per-GiB billing avoids that cliff.
ElastiCache Serverless: priced per GB stored and per request unit
- Storage: 100 GB × $0.084 × 730 = $6,132/month
- ECPUs at 10,000 per second, sustained: ~26.3 billion/month × $0.0023 per million = ~$60
- ECPUs at 50,000 per second, sustained: ~$302
Serverless removes all capacity planning but costs about three times a right-sized node cluster at a steady 100 GB.
Redis Cloud: not publicly priced at 100 GB
Redis Cloud publishes its floors ($5/month Essentials, $0.014/hour and $200/month minimum Pro). For a 100 GB production database it points you to its calculator or sales team. Its largest Essentials plan, 100 GB on Redis Flex, serves part of the data from SSD and is capped at 20,000 ops/sec and 10,000 connections, so it isn't a like-for-like in-memory option. A third-party review (Aug 2026) reports a 10 GB HA Pro database at $549/month (REPORTED). Don't scale that figure linearly to 100 GB; get a quote.
Where the cost catches you
- Memory headroom. Redis needs room for fragmentation, replication buffers and spikes. Budgeting 100 GB of data as exactly 100 GB of capacity risks evictions or out-of-memory errors on every platform.
- ElastiCache node steps. Memory comes in fixed node sizes, so a dataset just over one node's usable memory forces the next layout up.
- Valkey vs Redis OSS on ElastiCache. The same nodes cost 20% less on Valkey. For most Redis clients, Valkey is protocol-compatible.
- Cross-AZ replication traffic on ElastiCache costs $0.01/GB. Write-heavy workloads with replicas in another AZ pay it on every replicated byte.
- Memorystore egress to other continents costs $0.08/GiB, and $0.02/GiB within North America. Same-region traffic is free.
- Backups: ElastiCache charges $0.085/GiB-month. Daily snapshots of 100 GB kept for a week add roughly $60/month.
Which one fits
- Lowest-effort HA at 100 GB on Google Cloud: Memorystore Standard, provisioned at 101+ GiB to land in the cheaper M5 tier.
- Lowest list price on AWS, with careful sizing: ElastiCache for Valkey on node-based clusters.
- Unpredictable load and no sizing work: ElastiCache Serverless, at roughly 3× the steady-state cost.
- Active-active multi-region or Redis Stack modules: Redis Cloud Pro. Budget for a quote, not a list price.
Assumptions
- 100 GB working dataset with one replica for HA, 730 hours/month, on-demand, no committed-use discounts
- Unit convention: the 100 GB dataset is modeled as 100 GiB (2³⁰-byte units) of memory, the unit Memorystore and ElastiCache size and bill in. A decimal 100 GB (10¹¹ bytes) is 93.13 GiB and lands in the same Memorystore M4 tier and the same ElastiCache layouts.
- us-central1 (Memorystore) and us-east-1 (ElastiCache)
- Excludes egress, backups and taxes unless stated
Pricing sources
- Memorystore for Redis pricing: https://cloud.google.com/memorystore/docs/redis/pricing
- Amazon ElastiCache pricing: https://aws.amazon.com/elasticache/pricing/
- cache.r7g.4xlarge price: https://instances.vantage.sh/aws/elasticache/cache.r7g.4xlarge
- Redis Cloud pricing: https://redis.io/pricing/
- Redis Cloud Essentials plan sizes: https://redis.io/docs/latest/operate/rc/subscriptions/view-essentials-subscription/essentials-plan-details/
- Redis Cloud pricing review (Aug 2026): https://upstash.com/blog/redis-cloud-pricing-in-2026-plans-costs-and-real-examples