Climatiq Alternatives: A Developer’s Field Guide
Most “Climatiq alternatives” lists put an emission-factor API and a six-figure enterprise platform in the same table, as though they were competing for the same purchase. They are not. This page sorts the field into the three categories that actually exist, says plainly when the right answer is to stay where you are, and includes the option no vendor page ever lists — using the open data directly and paying nobody.
If you need an API, your substitutes are other emission-factor APIs — and the reason developers go looking is usually that Climatiq’s pricing table marks API access unavailable on all three published-price plans — it is an Enterprise feature, at a price they do not publish — while the free Starter plan is licensed non-commercial. If you need a finished inventory product, you are shopping for a platform, not an API, and price comparisons between the two are meaningless. If your scope is one country and a handful of activities, the honest answer may be neither: the publishers give this data away.
What Climatiq is, and where it is genuinely strong
Climatiq is an emission-factor and calculation API: a searchable library of factors aggregated from many published datasets, with endpoints that turn an activity into an emissions figure. It is one of the more established products in this category, and any fair page has to start with what it does well.
Breadth is real. Climatiq maintains a substantially larger factor library than we do, across more datasets and more activity types. If your inventory needs a long tail of niche activities under one roof today, they are the more complete catalogue and we are not going to pretend otherwise.
Maturity is real. They have been at this longer, with an established customer base and a product-carbon-footprint toolchain that we do not offer at all. If PCFs with audit documentation are the job, that is squarely their lane and not ours. Their PCF API completed a third-party audit against ISO 14067 and the GHG Protocol Product standard in June 2026.
Their provenance is good, and it is the bar. A Climatiq estimate returns the source, the source dataset, the year, the region, the LCA activity, the GWP basis it used (AR4, AR5 or AR6), whether Climatiq or the publisher did the CO2e arithmetic, a per-gas breakdown, and data-quality flags. Reproducibility is handled by pinning a data_version — a fixed value gives repeatable results, a caret-prefixed one adopts non-breaking updates. Anyone claiming this category has no serious incumbent has not read their docs.
Their reliability record is good. Their public status page lists sixteen incidents across its entire history, three of them in 2026 and none of those major. That deserves saying plainly on a page like this.
What the 1.7 million actually is
Climatiq’s homepage advertises more than 1.7 million emission factors. That number is real, and it is worth understanding before you treat it as a coverage comparison.
Their public source directory lists 76 named sources, and the distribution is extremely top-heavy: a single source — CEDA, a spend-based dataset — accounts for roughly 872,000 of those rows, about half the headline, and the top seven sources together account for around 1.59 million of the 1.7 million. A spend-based dataset expands across years, regions and price bases, so a row count of that size reflects that expansion rather than that many distinct measurements. Their own documentation, meanwhile, describes the database as “more than 40 sources, 80 datasets” — against “140+ trusted datasets” on the homepage.
The second thing worth knowing is that roughly 476,000 of those factors — about 28% — are marked Premium, meaning a separate licence on top of your subscription. ecoinvent, IEA, sustamize and Carbon Minds all sit behind that second gate. A headline factor count is not a coverage promise; ask which of it your plan actually reaches.
CEDA — the single largest contributor to that 1.7 million — is owned by Watershed, who publish Open CEDA free under CC BY-SA: around 60,000 spend-based factors across 400 industries and 148 countries, updated annually. It is a download rather than an API, and it is spend-based only, so it is not a substitute for a general catalogue. But if spend-based Scope 3 is what you actually need, the largest single source behind the headline number is available to you for nothing.
If Climatiq covers your activities, and your use is compatible with the plan you are on, switching costs more than it saves. Factor keys, regional coverage and methodology choices do not line up between vendors, so migration means a mapping review, not a change of base URL — and every figure you have already reported was computed on the source you are leaving. “It is cheaper elsewhere” is rarely a sufficient reason on its own.
Why teams go looking — the three real triggers
Nearly every search for an alternative traces back to one of three things, and they call for completely different answers.
The licence, not the price
Climatiq’s free Starter plan is labelled “Non-commercial license” on its own pricing page, alongside “search and browse emission factors with limited metadata”. Teams that prototyped on it discover the restriction when the prototype becomes a product. No quota increase fixes a licence.
The step to API access
Climatiq publishes three prices — Starter (free), Data Pro (€250/month or €2,000/year) and PCF Pro (from €4,900/year). Its own comparison table marks API access unavailable on all three, and available on Enterprise, which is quoted rather than published. Their pricing FAQ says the same thing in words: asked whether you can buy Data Studio and API access together, the answer is to get in touch about an enterprise plan. A developer who simply wants programmatic access has no self-serve route at all.
Category mismatch
Some teams arrive at an API and discover they wanted a product: they do not want to build a footprint tool, they want to have one. That is not an argument against Climatiq. It means the whole shortlist is in the wrong category.
Climatiq’s licensing page states that on cancellation, “data retrieved from Climatiq while a license was valid can no longer be used for commercial purposes going forward.” That is not unusual and it is clearly disclosed — but it means the figures already sitting in your database are covered by a licence you no longer hold. Whatever vendor you choose, find the equivalent clause and decide what it means for the reports you have already published. It is the single most consequential sentence in most of these agreements and the one nobody reads.
Prices and plan structures move, and this category moves faster than most: Climatiq deprecated its Energy v1 endpoint in July 2026, retires Freight v2 at the end of this month, and its Cloud Computing endpoint has been withdrawn entirely — it now returns a not-found error and appears in neither the changelog nor the deprecation calendar. Their published policy is a three-month window for preview endpoints and a minimum of one year for generally available ones. Everything above was read from Climatiq’s own pricing page and docs on 8 September 2026 — check it before you make a decision on it, and if we are out of date, tell us and we will correct it visibly.
First, sort the field
The reason most alternatives lists are useless is that they put three different kinds of product in one table. Before comparing anything, work out which you are actually shopping for, because it changes what a fair comparison even looks like.
Emission-factor APIs and data layers
You have an application. It needs numbers, with enough context to defend them. You write the product; the vendor supplies the data and usually some calculation endpoints. This is Climatiq’s category, and the only one containing true substitutes.
Carbon accounting platforms
You do not want to build anything. You want software that collects activity data, computes an inventory and produces a report someone will sign. These fill every alternatives list and are not alternatives in any meaningful sense — different purchase, different budget, sales cycle attached.
Open data and your own code
The publishers give their factors away. You could download DEFRA, EPA and ADEME yourself and pay nobody. A real option that no vendor’s comparison page will show you, and for some teams the right one. It has a cost; it is just not an invoice.
If you find yourself comparing a per-call API price against a platform’s annual licence, stop — you are comparing a component with a finished product. Those two numbers cannot be made comparable, and the exercise will mislead whoever reads it.
Category A: the direct substitutes
Within the API category there is a second split worth making, because it decides whether a vendor is a replacement or a supplement.
Full-catalogue factor APIs aim to cover many activity types across many domains — fuels, electricity, transport, materials, spend. These are the genuine substitutes. Single-domain data APIs cover one slice, usually electricity, in far more depth than any general catalogue. They are not replacements for Climatiq; they are what you reach for when one domain matters more than the rest, often alongside a general source.
| API | Scope | Free tier | Commercial use free? | Published entry price |
|---|---|---|---|---|
| Climatiq | Full catalogue + PCF | Starter, browse with limited metadata | No — non-commercial licence | €250/mo for data; API is Enterprise-only, unpriced |
| GreenCalculus | Full catalogue + calculations | Keyless browse; 1,000 calls/mo with a key | Yes, in your own application | $49/mo |
| CarbonAPI (carbonapi.io) | Spend and supplier emissions, expense categorisation | 1,200 credits, no card | Not stated publicly | From $250/mo |
| Carbon Interface | Estimates: electricity, flights, vehicles, shipping | 200 requests/month | Terms are silent either way | $30/mo |
| ecoinvent API | Life-cycle inventory, the LCA reference database | Four-week trial — returns placeholder values, not real data | Licence required | No published price |
| Electricity Maps | Single domain — live grid carbon intensity | 14-day trial; standing free access for academics and Home Assistant | Trial only | €6,000 per country/year for carbon intensity |
| Ember | Single domain — electricity generation and intensity | Free key, no published rate limit | Yes — CC BY 4.0 | No paid tier exists |
| Climate TRACE | Single domain — asset and country emissions inventories | Keyless, no account | Yes — CC BY 4.0 | Free |
| WattTime | Single domain — marginal grid emissions signals | One region for most endpoints | No — Noncommercial Agreement | No published price |
What the table does not tell you
CarbonAPI is the strongest genuine competitor we found on the dimension this page cares most about, and it beats both Climatiq and us on one axis. Its factor object returns a resolvable sourceUrl — a link to the source material rather than a name for it — plus sourceVersion, sourceDataYear, the valuation method, and a matchType field that flags when a value is a modelled match from a previous year rather than a direct one. Publishing “this number is an approximation and here is why” in the payload is rare and good. Their own caveat is that the categorisation is AI-driven and outputs should be reviewed.
ecoinvent is the reference database underneath much of the LCA world, and it launched its own API commercially in June 2026. Three things matter before you design around it. There is no published price for any licence tier. The four-week trial returns placeholder values rather than real environmental data, by their own documentation, so it validates your integration and tells you nothing about the numbers. And the licence draws a hard line between computing with the data and passing it on: distribution beyond a handful of data points is barred, dynamically publishing results through a software tool is barred, and usage reporting is a contractual obligation that extends to cached data. If your product needs to show people factor values, read that licence before you design the feature.
Carbon Interface is the closest thing to a low-friction commercial substitute at the small end, at $30 a month for 5,000 requests. The gap worth knowing about is that its terms of use address the website and user content but say nothing about what you may do with the estimates the API returns. Silence is not permission; it is an unresolved question you are carrying.
The single-domain APIs are frequently the better answer for the thing they cover. If your product lives or dies on grid carbon intensity, a general catalogue’s annual national averages are not what you need, and no amount of breadth substitutes for a purpose-built source. Several teams end up with one general source plus one specialist, which is a sensible architecture rather than a failure to choose.
If your comparison is specifically against a grid-data vendor rather than a general catalogue, we keep a separate page on that, because the jobs are genuinely different.
Category B: when a platform is the right answer
Watershed, Persefoni, Normative, Greenly, Plan A, Sweep and their peers appear on nearly every “Climatiq alternatives” list. They are excellent at something Climatiq does not do, and poor substitutes for what it does.
A platform ingests your activity data, computes your organisation’s inventory, and produces disclosure-ready output with a workflow and an audit trail around it. It is bought by a sustainability lead, priced annually, and sold through a sales process. An API is bought by an engineer, priced by usage, and integrated in an afternoon.
The test is simple: are you producing your own company’s footprint, or are you building software that computes footprints? The first is a platform purchase and the API question does not arise. The second is an API purchase and a platform will not help you, because you cannot build a product on someone else’s reporting workflow.
Two of them publish real prices, and deserve credit for it. Zevero lists annual figures from £1,500 to £7,500 by tier, with per-product pricing for footprints and EPDs; Carbonhound publishes $600 to $5,700 a year by headcount band with a 14-day trial. In a category where almost every vendor answers “how much?” with a calendar invite, publishing the number is a real courtesy to buyers. Neither has a developer API, so neither is a substitute for Climatiq — but if you are in the platform category, start with the ones that will tell you the price.
Names on other lists that no longer exist
This category has consolidated hard, and the listicles have not kept up. Every one of the following was checked on 8 September 2026, and each is a link a reader would otherwise waste time on.
| Name on the list | What actually happened |
|---|---|
| Emitwise | Acquired by Green Project Technologies in July 2025. Their own site states it is no longer sold as a standalone product or brand. |
| Optera | Acquired by Green Project Technologies, announced July 2026 — and usually reported the wrong way round. optera.com no longer resolves. |
| ecolytiq | Acquired by Clarity AI in July 2025. No live vendor site; any figure still circulating is second-hand. |
| Plan A | Acquired by Diginex, announced January 2026 — but alive. Brand and product continue, so this one stays on your shortlist. |
| CarbonSmart | The API page is still search-indexed and now returns a 404. |
| “Sweep” | Two different companies. The carbon and ESG one is sweep.net; sweep.io is a Salesforce metadata product. Citing the wrong one is a visible error. |
| “Beacon”, “Impact Labs” | Neither is a carbon-data API. The first maps to a freight platform and unrelated products; the second is a consultancy. |
One API in this space, technically among the better-documented we reviewed, names its operating company on its own about page — and the UK companies register lists that company as dissolved, in July 2026, while the service continues to take card payments. We are not naming it here because circumstances change and a register entry is a snapshot; the point is the check. Before you make any vendor a production dependency, spend two minutes on the corporate register for whatever jurisdiction they claim. It is the cheapest diligence available and almost nobody does it.
We deliberately do not compare ourselves feature-by-feature against platforms — it would be a category error in our favour, which is the easiest and least useful kind of comparison to win. The longer version of the distinction, including the cases where the platform is plainly the right call and we are not, is at carbon platform or carbon data API.
Category C: open data and your own code
No vendor comparison page includes this option, because it sells nothing. It belongs here, because for a meaningful number of teams it is the correct answer.
The major publishers give their factors away. DEFRA and DESNZ publish the UK conversion factors under the Open Government Licence; the EPA’s Emission Factors Hub, eGRID and the USEEIO supply-chain factors are US Government works in the public domain; ADEME publishes Base Carbone under Licence Ouverte. If your scope is one country and a handful of activities, downloading a spreadsheet and writing a lookup is a sensible afternoon’s work, and you will owe nobody anything.
What you take on is not the first version. It is the second year. From maintaining exactly this ourselves, the costs that arrive later are:
| The job | What it actually involves |
|---|---|
| Tracking releases | Publishers do not announce on a shared schedule. DEFRA ships each June, the EPA each January — except when it does not: neither eGRID2024 nor the 2026 Emission Factors Hub has appeared, with no statement of cause. Somebody has to notice. |
| Absorbing the changes | Across one 112-day window we recorded 2,219 published factor values changing, a median move of 5%, with 93% landing inside a single fortnight. Re-checking hard-coded values is not an annual afternoon; it is a burst you cannot schedule. |
| Reading the licences | We licence-reviewed 167 sources and found 122 distinct licence strings; 76 may not be redistributed at all — which matters the moment your product exports a factor table to a customer. The database landscape guide covers which, and why. |
| Normalising units and bases | Publishers disagree on units, on gases, and on which IPCC assessment’s global warming potentials they applied. Mixing an AR5-based factor with an AR6-based one is a silent error that yields a plausible wrong number. |
| Pinning versions | To explain why a 2025 report differs from today’s figure you need the value as it stood then. That means archiving every edition you used and being able to address it. |
None of that is hard. All of it is permanent, and it lands on whoever built the lookup, usually while they are meant to be doing something else. The honest test is whether emission factors sit close enough to your product’s core that you want to own that maintenance forever. If they do, own it — the data really is free. If they do not, that maintenance is the actual thing an API sells you, and the factor lookup is merely how it is delivered.
We wrote a longer, first-person version of this trade-off in DEFRA spreadsheets versus an emission-factor API, including the cases where the spreadsheet genuinely wins.
The five questions that actually decide it
Feature tables are easy to win and easy to fake. These five are harder to answer and much harder to fake, and they predict how an integration feels in year two rather than in week one.
Is the price published?
Not “is it cheap” — is the number on a page you can read without talking to anyone. A published price is a commitment you can plan against. “Contact sales” is not a price; it is a negotiation, and it usually means the number depends on what they think you can pay.
May the free tier be used commercially?
A licence question wearing a pricing question’s clothes, and the one that catches teams six months in. Several free tiers in this category are explicitly non-commercial, which no quota increase fixes. Read the terms, not the pricing table.
What does a response say about where the number came from?
Call the API and read the payload. Does it name the publisher, the exact table or cell, the year, the region, the GWP basis, the date it was read? A value with no lineage is a number you will later have to defend using evidence you do not have.
Can you reproduce last year’s answer?
Factors change in bursts. If an auditor asks why a 2025 figure differs from today’s, you need to pin the version you used, not explain the drift. Ask whether the vendor archives versions and lets you address them.
What does the vendor say it does not have?
Everyone publishes coverage. Almost nobody publishes absence. A vendor that can name the factors it lacks — and say whether that is because no publisher issues them or because it has not got to them — has actually looked. One that answers everything with “yes, we have that” has not.
Evaluate any of them in ten minutes
Four checks, none requiring a sales call. Run them against every vendor on your shortlist, including us.
- Try to get a number without talking to anyone. How long from landing page to a value in your terminal? That interval is a fair proxy for what the whole relationship will feel like.
- Read one response in full. Not the docs — an actual payload. Everything you will ever be able to tell an auditor is in there, and it is usually less than the marketing implies.
- Ask for the same factor pinned to two different dates. If a vendor cannot express “the value as it stood in June 2025”, reproducing an old report means keeping your own copies — the maintenance you were trying to outsource.
- Search the terms for “non-commercial”, “redistribute” and “attribution”. Ten minutes with the licence beats a year of assuming. What the data costs matters less than what you are permitted to do with it.
Our corpus answers the first three with no key, so you can run the test on us before deciding whether we are worth an account:
curl "https://api.greencalculus.com/v1/factors?search=natural+gas&limit=1"That returns the value, the publisher, the exact source table and row, the retrieval date, the GWP basis, a gas-by-gas breakdown, and the licence of the source it came from. We are not claiming the others cannot do this — we are saying it takes ten minutes to find out, and it is the check most people skip.
Where we fit, and where we do not
We are one of the options on this page, so here is our own entry written to the same standard as everyone else’s — including the parts that argue against us.
What we are. An emission-factor API with provenance as the product. Every value returns the publisher, the exact source table or cell, the retrieval date, the GWP basis and a gas-by-gas breakdown, plus the licence of the source behind it. The corpus is browsable with no key and no account, so you can audit us before signing up. The free tier is 1,000 calls a month with commercial use permitted, and paid plans start at a published $49 a month.
Where we are weaker. Our catalogue is smaller than the largest aggregators’. We do not offer a product-carbon-footprint toolchain at all. We are a younger product with a shorter operating history. If you need a long tail of niche activity factors under one roof today, that is a real reason to choose someone else, and we would rather say so than have you discover it in week three.
What we publish that most vendors do not. An absence register: a machine-readable list of what we do not have, and why. It currently holds 12 documented gaps — nine where no publisher issues the data anywhere, one coupled to another gap, one we found and declined on licence grounds, one we have simply not surveyed. Each carries the publishers checked, the route tried, a confidence and a review date. It is not a flattering document, which is the point: you can hold it against us, and you cannot hold against a vendor what it never tells you.
If you have narrowed the field to us and Climatiq specifically, we keep a direct head-to-head comparison that opens with where they are stronger and dates every claim to the day it was checked. That page is written in the first person and makes our case; this one is not, which is why they are separate documents.
Frequently asked questions
Yes, with a caveat that matters more than the price. Several carbon APIs have free tiers, but two of the best known license theirs for non-commercial use only — free of charge, and not usable in a product that earns money, at any volume. The genuinely free-for-commercial-use options are a shorter list, and the underlying open datasets are free to everyone. We compared what each vendor means by the word in free carbon APIs that are actually free.
Not on price alone. Switching a factor source is not swapping one endpoint for another: keys differ, coverage differs, and every figure you have already reported was computed on the source you are leaving. If Climatiq covers your activities and the licence permits what you are building, staying is usually cheaper than moving. The reasons to move are structural — you need provenance they do not expose, you need a category they do not serve, or the terms do not permit your use.
An API is a component you build with; a platform is a finished product you operate. If you are writing software that needs emission factors, you want the API. If you need to produce your own company’s inventory and report it, you want the platform, and the engineering question does not arise. Confusing the two is the commonest mistake on alternatives lists, because platforms have marketing budgets and APIs mostly do not.
The integration is the easy half — usually a day. The hard half is that factor keys, regional coverage and methodology choices do not line up between vendors, so a subset of your activities will map imperfectly and someone must decide what to do about each. Budget for the mapping review, not the code. And keep the old figures with a note of which source produced them; restating history is a bigger decision than changing supplier.
Yes, and for a narrow scope you probably should — both publish under terms permitting commercial use and redistribution. What you take on is the maintenance: tracking releases nobody announces to you, absorbing changes that arrive in bursts, reading licences that differ per source, and archiving versions so you can reproduce an old report. That work is what an API actually sells. Whether it is worth paying for depends on how close emission factors sit to your product’s core.
Because a comparison that always concludes in the author’s favour is worth nothing to the reader, and we would rather lose a customer we were wrong for than win one who leaves in six months. There are situations on this page where the honest answer is a competitor, and they are named. If you catch this page shading the truth about anyone, tell us and we will correct it visibly — that promise is the only thing that makes the rest of it worth reading.