Credits are a shared quota across all diff types. Each diff consumes credits based on the size of the input — for example, a text diff uses 1 credit per 300,000 characters, a PDF plain text diff uses 1 credit per 3 pages, and a PDF rich text diff uses 1 credit per page. You can use your credits on any combination of diff types.
Diffchecker API
Use the Diffchecker API to compare text, documents, images, and spreadsheets programmatically. A powerful document comparison and file diff API for developers.
Credit Usage
Credits are shared across all diff types. Each type consumes credits based on input size.1
| Diff type | 1 credit = |
|---|---|
Text | 300,000 characters |
Image | 4,000,000 pixels |
PDF (plain text) | 3 pages |
PDF (rich text) | 1 page |
Excel | 15,000 cells |
- 1 Credit usage is calculated based on the larger of the two documents being compared.
Query Parameter Multipliers
Some query parameters increase compute cost and apply a multiplier to base credit usage.
| Diff type | Parameter | Multiplier1 |
|---|---|---|
PDF (rich text) | page_image_scale ≤ 1 | 1x |
page_image_scale 1 - 2 | 1.50x | |
page_image_scale 2 - 3 | 2x | |
page_image_scale 3 - 4 | 3x | |
Any visual toggle enabled2 | 1.50x |
- 1 Multipliers stack. For example,
page_image_scale=2.5(2x) with a visual toggle enabled (1.5x) costs 3x the base credits. - 2 Visual toggles include
compare_regular_images,compare_vector_graphics,compare_form_xobjects, andcompare_shading_objects. Enabling multiple visual toggles at the same time does not stack; the 1.5x multiplier is applied once.
Credit Calculator
Estimate how many credits a single API call will use.
Diff type
Left document (characters)
Right document (characters)
Estimated credits
0
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Frequently Asked Questions
Credits reset automatically when your subscription renews. For monthly plans, this happens every month. For yearly plans, credits reset once per year at renewal.
Once you've used all your credits, additional API requests will return an error until your credits reset at the start of your next billing period. You can upgrade your plan at any time to get more credits.
Yearly plans offer a 17% discount compared to paying monthly. Yearly plans also come with 12x the credits, which reset once per year instead of monthly.
Paid plans use API key authentication. After purchasing, you'll receive an API key that you include in the X-Api-Key header of your requests. Free tier users authenticate with their email address.
The API supports text diffs, image diffs, PDF diffs (plain text and rich text), and Excel diffs. All diff types draw from the same credit pool.
You can upgrade your plan at any time. Contact us if you need to make changes to your subscription.
To request a refund, please fill out our contact form within 30 days of your purchase.
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