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Compare two cloud billing periods

See what changed in your cloud spending, and how much came from usage versus your effective cost per unit.

Multi-cloudReads your own dataBring a file

Upload an earlier and a later billing export, or try the sample data. No cloud connection required.

New here? See what this tool does, how to use it and how to get your data.

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Cloud Bill Diff

What this free tool does for you

When the cloud bill jumps, explain why before finance asks. See, service by service, how much came from using more and how much from paying a higher price, so you fix the right thing.

How to use it

  1. Click Try sample data, or drop the earlier month's export into Earlier billing period and the later one into Later billing period.
  2. Leave Adjust for different period lengths ticked, so a 28-day and 31-day month compare fairly. Then check Are the two files comparable?
  3. Read the total change, split into Usage change and Effective unit-cost change, then How the change adds up for new and removed items.
  4. Open a service under Largest cost changes to see which line items moved, then click Download the breakdown as CSV.
  5. What the data shows is the evidence and Worth investigating is suggestions. Check a unit-cost rise in the Commitment Coverage Checker.

Good to know

  • Private. Your files are read in this browser tab, and sent only if you choose to share them for a review. Account IDs are masked on screen; SKU names are not.
  • Does not match your invoice? Tax, credits and purchases are left out unless you tick Include tax, credits, and purchases. Google Cloud committed and sustained use credits are always netted in, as part of the price.
  • Where to get the files. See How to get your billing export further down the page. AWS, Google Cloud and FOCUS exports all work. A month in several files? Choose them all at once.

Not sure where to get the data? .

An AI assistant's cloud bill increased from $750 to $1,070. See how much came from more token usage versus higher infrastructure costs. Made-up data, April and June 2026.

Earlier billing period

or drop a CUR, GCP billing export, or FOCUS file here. .csv and .csv.gz. A month in several files? Choose them all.

Later billing period

or drop a CUR, GCP billing export, or FOCUS file here. .csv and .csv.gz. A month in several files? Choose them all.

Compares average daily spending, so longer months do not look more expensive just because they have more days.

More options

Files are processed locally in your browser, and sent only if you choose Share for a review. Account and project IDs are masked by default. Review screenshots and downloaded results before sharing; costs and other business details may still be sensitive.

Want this done on your real bill?

Cloud Cost Audit: We go through your real AWS or Google Cloud bill and hand you a ranked list of what to cut first. From $1,500, fixed. Nothing paid upfront.

See the service

Useful for investigating the cloud costs behind production agents. Separately billed model APIs and external tools are not included unless their charges appear in your uploaded data.

Before you start: what to have readyShow
  • Two billing exports, ideally two whole months. The tool compares them per day, so a 28-day month and a 31-day one compare fairly. A partial month against a whole one still misleads: a month-to-date export misses the month-end charges.
  • The same scope in both. The same accounts, projects or subscriptions, the same currency, and the same treatment of credits and taxes. A scope change between the two files reads as a cost change.
  • The same cost basis. Export both files the same way: both amortized, or both as billed. Otherwise a reservation purchase shows up as a spike in one month and a saving in the next.

Questions

Why did my AWS bill go up?

For comparable usage items, the tool separates changes into usage and effective unit-cost effects. New services, account scope, credits, taxes, commitment charges, and incomplete billing periods can also affect the comparison, and are shown as their own lines. A higher unit cost can come from a discount or commitment ending, a pricing tier or a billing adjustment, not only a price change; the billing data alone cannot say which.

What files does it accept?

AWS Cost and Usage Report (both CUR 2.0 from Data Exports and the legacy format), the GCP billing export from BigQuery, and any FOCUS 1.x dataset. CSV and gzipped CSV. Azure works through a FOCUS export. Both periods must be the same kind of export in the same currency; the tool says so and stops if they are not.

Is my billing data uploaded anywhere?

Files are processed locally in your browser. They are sent only if you use "Share for a review" and tick its consent box. The site records anonymous usage events, such as the detected file format and a size band, never file names or contents; the /privacy page lists them. Account and project IDs are masked by default: shown as a short code instead. SKU names, costs and the CSV download are not masked, so review screenshots and downloaded results before sharing.

How do you separate usage from unit cost?

For each SKU and pricing unit, the effective unit cost is cost divided by quantity in each period. The usage change is the change in quantity at the average of the two unit costs; the unit-cost change is the change in unit cost at the average of the two quantities. The two add up exactly to that SKU's change (the symmetric convention: 1,000 units at $0.10 becoming 1,500 at $0.12 is $55 usage and $25 unit cost). SKU results are summed to services and the total, never recomputed from added-up quantities. New, removed and not attributable items are separate lines. The full method is on the "How rate and usage are separated" page.

Why does the total not match my invoice or Cost Explorer?

By default the analysis covers usage charges only, and adjusts for period length, so the figures are per day; the period totals are shown under the headline. Neither is an invoice total. Tax, credits, and commitment purchases are shown separately as reconciling lines: a Reserved Instance purchase is a cash event, not a change in run rate, and folding it into usage would be misleading. The Cloud Invoice Reconciler matches an export to an invoice.

How to get your billing export →How rate and usage are separated →Score the same file for tag coverage →

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More tools for: Billing data, allocation and governance

Two files is a snapshot. Your bill moves every day.

Finitizer runs this decomposition continuously across AWS and Google Cloud, alerts on the movements that matter, and traces each one back to the resource and the team that owns it, so the answer arrives before the invoice does.

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