Amazon S3 to Backblaze B2,
with the storage bill on a diet.
The other major cost-arbitrage move. Backblaze B2 storage is roughly a sixth the price of S3, S3-API compatible, with predictable monthly bills — popular for backup, archival, and media workloads.
Mover handles S3 → Backblaze B2 end to end. Authorize an S3 access key, authorize a B2 application key, see the price before any bytes move. The dry run is free and shows the AWS egress estimate alongside the Mover fee.
From
Amazon S3
To
Backblaze B2
Why teams move from S3 to Backblaze B2.
Like Wasabi, B2 wins on storage rate and on bill predictability. The difference is in the egress pricing: B2 includes a free egress allowance proportional to stored data, then charges a flat per-GB rate above it — usually substantially cheaper than S3.
Storage at roughly a sixth the per-TB cost
B2's headline rate is among the lowest in the market. For backup, archival, and cold-tier workloads the recurring savings vs S3 standard are large enough to justify the one-time migration on a single year of usage.
Generous free egress + low egress beyond that
B2 includes free egress equal to 3x your monthly stored data, then charges a flat per-GB rate (typically much less than S3's $0.09/GB). For typical backup-and-restore patterns, the included egress covers the workload entirely.
S3-API compatible
B2 supports the S3 API. Existing S3 tooling, backup clients, and scripts mostly need only an endpoint change to point at B2 — minimal integration work after the migration.
Predictable bill structure
B2 pricing is flat per-TB-per-month for storage and flat per-GB beyond the free egress allowance. No tier-transition fees, no Glacier-class restoration charges, no surprise line items. Finance sees the same number every month for the same data.
4 steps to Go.
From credential to first byte in a handful of clicks. The dry-run is free, every time, and shows the exact cost before you commit a byte.
Connect Amazon S3.
Provide an IAM access key with read on the source bucket. Mover supports scoped, least-privilege credentials and stores keys in an encrypted credential store.
Connect Backblaze B2.
Provide a B2 application key with write access to the destination bucket. Mover authenticates against the B2 endpoint for the right region.
Run a free dry run.
Mover walks the S3 source, sums bytes, and produces an exact-cost estimate that includes Mover fees and the AWS egress estimate. The dry run is free, every time.
Launch the migration.
Live progress, multipart parallelism, automatic retries on transient failures, structured audit log of every object moved.
The pricing math, honestly.
S3 charges egress (typically $0.09/GB at standard rates). Backblaze B2 charges nothing for ingress. The line items are Mover (as low as $0.15/GB on a 10 TB pack) and AWS egress. The dry run shows both numbers at the dollar before you commit.
10 TB S3 → Backblaze B2 migration
AWS egress varies by region and committed-use discounts. The dry run shows the exact AWS-side cost for your data.
See your twelve-month savings.
Move from a paid-egress provider to one with free egress and your monthly invoice shrinks. Plug in your data size and how much you read from storage each month — the calculator does the rest, including the one-time Mover migration cost.
Current cost on Amazon S3
per month
$348
New cost on Backblaze B2
per month
$31
Monthly savings
recurring
$317
One-time Mover migration
1× 5 TB + 1× 100 GB
$848
12-month savings
$3,809
Before subtracting the one-time migration cost.
Payback period
2.7 mo
$848 migration ÷ monthly savings.
Net savings, year one
$2,961
Numbers use published standard-tier rates from each provider as of May 2026. Actual invoice varies by region, committed-use discounts, and your specific contract. Mover migration cost uses the cheapest combination of prepaid usage packs that covers the data size — packs stack, so a 2 TB migration is two 1 TB packs, not one 5 TB pack. The dry run prices the migration against your actual data and shows the exact one-time Mover cost before you commit.
Frequently asked.
Most teams launch their first migration in under 15 minutes. The dry run is free, every time.
Run a free dry run. Connect Amazon S3 and Backblaze B2, and Mover walks the source, counts every file, sums the bytes, and returns the exact file count and price before you commit. Buy the matching usage pack, launch, and Mover handles the transfer — re-running later moves only what changed or failed.
Both are S3-compatible discount storage. Wasabi's headline is "no egress fees at all (within fair-use)"; B2's is "free egress allowance proportional to stored data, then flat per-GB." For workloads with moderate, predictable egress, both work well. For workloads with very high egress relative to stored data, Wasabi tends to win; for steady-state storage with light reads, B2 tends to win on storage rate.
Object metadata (Content-Type, custom headers) is preserved. S3 ACLs don't map 1:1 to B2; bucket-level and key-level access are reconfigured on the B2 side after the migration. Mover migrates the data; access controls are re-established at the destination.
Glacier and Deep Archive objects need to be restored to S3 standard before Mover can read them. Restore latency depends on the Glacier tier (Glacier Instant Retrieval is fast, Deep Archive is hours). The dry run flags Glacier-tier objects in the source so you can plan the restore.
Yes. Filters on the S3 side narrow the source to specific prefixes, date ranges, or object-name patterns. Useful for staged cutovers where you move one workload at a time.
Multipart parallel transfers respecting S3 and B2 API rate limits. For multi-TB migrations the bottleneck is usually the S3 read rate or the B2 write rate — both of which Mover saturates without manual tuning.
Move S3 to Backblaze B2 and shrink the storage bill.
Connect both sides, run a free dry run, see the exact cost — including AWS egress. Launch when you are ready.